The function appends the username and password, both URL-encoded, to the specified URI. It can be useful for cases where you need to specify a username and password in an HTTP request, and either the username or the password or both contain special characters that need to be escaped.

Set-UriUserInfo.ps1

#Requires -Version  5.1
#Requires -Assembly "System.UriBuilder, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
#Requires -Assembly "System.Web.HttpUtility, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"

<#
.SYNOPSIS
    The function appends the username and password, both URL-encoded, to the specified URI.
.DESCRIPTION
    The function appends the username and password, both URL-encoded, to the specified URI.
    It can be useful for cases where you need to specify a username and password in an HTTP request, and either the username or the password or both contain special characters that need to be escaped.
.PARAMETER Uri
    Specifies the input URI. If the source URI already contains a username and password, these credentials will be replaced.
.PARAMETER Credential
    Specifies the credentials in a secure form to append to the source URI.
.PARAMETER UserName
    Specifies the username in plain text to append to the source URI.
.PARAMETER PassPlain
    Specifies the password in plain text to append to the source URI.
.EXAMPLE
    PS C:\> Set-UriUserInfo -Uri 'https://site.contoso.com/site/path?and=query' -UserName 'sampleLogin' -PassPlain 'P@s$w0:rD!'
    The function appends the username and password, both URL-encoded, and returns this URI:
    https://sampleLogin:P%40s%24w0%3arD!@site.contoso.com:443/site/path?and=query
.EXAMPLE
    PS C:\> 'https://site.contoso.com/site/path?and=query' | Set-UriUserInfo -UserName 'sampleLogin' -PassPlain 'P@s$w0:rD!'
    The function appends the username and password, both URL-encoded, and returns this URI:
    https://sampleLogin:P%40s%24w0%3arD!@site.contoso.com:443/site/path?and=query
.EXAMPLE
    PS C:\> Set-UriUserInfo -Uri 'https://site.contoso.com/site/path?and=query' -Credential 'sampleLogin'
    The function asks for the credential, then decodes them, appends the extracted username and password, both URL-encoded, and returns this URI:
    https://sampleLogin:P%40s%24w0%3arD!@site.contoso.com:443/site/path?and=query
.EXAMPLE
    PS C:\> 'https://site.contoso.com/site/path?and=query' | Set-UriUserInfo -Credential 'sampleLogin'
    The function asks for the credential, then decodes them, appends the extracted username and password, both URL-encoded, and returns this URI:
    https://sampleLogin:P%40s%24w0%3arD!@site.contoso.com:443/site/path?and=query
.INPUTS
    [System.Uri]
    [System.Management.Automation.PSCredential]
    [System.String]
.OUTPUTS
    [System.Uri]
.NOTES
    It can be useful for cases where you need to specify a username and password in an HTTP request, and either the username or the password or both contain special characters that need to be escaped.
    Specifying credentials in plain text is a bad idea, yep.
.LINK
    .
#>

function Set-UriUserInfo {
    [CmdletBinding()]
    [OutputType([uri])]
    param   (
        #   Specifies the input URI. If the source URI already contains a username and password, these credentials will be replaced.
        [Parameter(
            Mandatory                       =   $true,
            ValueFromPipeline               =   $true,
            ValueFromPipelineByPropertyName =   $true,
            Position                        =   0
        )]
        [uri]
        $Uri,

        #   Specifies the credentials in a secure form to append to the source URI.
        [Parameter(
            Mandatory                       =   $true,
            ValueFromPipelineByPropertyName =   $true,
            ParameterSetName                =   'Credential',
            Position                        =   1
        )]
        [pscredential]
        $Credential,

        #   Specifies the username in plain text to append to the source URI.
        [Parameter(
            Mandatory                       =   $true,
            ValueFromPipelineByPropertyName =   $true,
            ParameterSetName                =   'UserPass',
            Position                        =   1
        )]
        [Alias('user')]
        [Alias('u')]
        [Alias('Login')]
        [Alias('l')]
        [string]
        $UserName,

        #   Specifies the password in plain text to append to the source URI.
        [Parameter(
            Mandatory                       =   $true,
            ValueFromPipelineByPropertyName =   $true,
            ParameterSetName                =   'UserPass',
            Position                        =   2
        )]
        [Alias('Password')]                 #   The word "Password" is specified as the parameter alias instead of the parameter name due to warnings displayed by PSScriptAnalyzer
        [Alias('pass')]
        [Alias('p')]
        [string]
        $PassPlain
    )
    begin   {}
    process {
        [System.UriBuilder]$uriBuilder  =   [System.UriBuilder]::new($Uri)
        if  ($PSCmdlet.ParameterSetName -eq 'Credential')   {
            [string]$UserName   =   $Credential.UserName
            [string]$PassPlain  =   $Credential.GetNetworkCredential().Password
        }
        $uriBuilder.UserName    =   [System.Web.HttpUtility]::UrlEncode($UserName)
        $uriBuilder.Password    =   [System.Web.HttpUtility]::UrlEncode($PassPlain)
        return  $uriBuilder.Uri
    }
    end     {}
}