This code snippet adds fields to the main Account tab.

um_account_custom_fields.php

<?php

// Add pre-defined fields to the main Account tab.
function um_account_tab_general_fields( $args, $shortcode_args ) {

	// Fields Meta Keys.
	$args .= ',birth_date';
	$args .= ',country';
	$args .= ',languages';

	return $args;
}
add_filter( 'um_account_tab_general_fields', 'um_account_tab_general_fields', 10, 2 );

This gist is a part of the article How to display pre-defined fields in Account.

You can add the code to the functions.php file in the child theme directory. You also may use the Code Snippets plugin to add a code snippet.

NOTE: This is a solution for pre-defined fields only. This code does not work with custom fields.
You can see all available predefined fields in the "Predefined Fields" section in the Fields Manager.

You can use a free extension Ultimate Member - Account tabs to display custom fields in Account. This extension can embed a profile form into the custom account tab.

Thanks, Could you add all list of this meta keys ? Or where is this list?

@BlackStar1991 the meta keys refer to the "column_headings" such as ID, user_name in the two tables "wp_users" and wp_usermeta". We define our own meta keys when creating a form with Ultimate Member. However, in my case, using these meta keys didn't work. I tried in many ways and could remove some of the fields from the default form but couldn't add a new field.

Text boxes are not being displayed.