IIS Reverse Proxy - avoid CORS

web.config

<configuration>
	<system.webServer>    
        <rewrite>
			<rules>
                <clear />
                <rule name="Reverse Proxy Rewrite URL">
                    <match url="proxy/(.+)" />
                    <conditions logicalGrouping="MatchAll" trackAllCaptures="false" />
                    <action type="Rewrite" url="https://{R:1}" logRewrittenUrl="true" />
                </rule>
                <rule name="OPTIONS returns 200" patternSyntax="Wildcard" stopProcessing="true">
                    <match url="*" />
                    <conditions logicalGrouping="MatchAny" trackAllCaptures="false">
                        <add input="{REQUEST_METHOD}" pattern="OPTIONS" />
                    </conditions>
                    <action type="CustomResponse" statusCode="200" statusReason="OK" statusDescription="OK" />
                </rule>
				
            </rules>
            <outboundRules>
                <rule name="Set-Access-Control-Allow-Origin to *">
                    <match serverVariable="RESPONSE_Access-Control-Allow-Origin" pattern=".+" negate="true" />
                    <action type="Rewrite" value="*" />
                </rule>
                <rule name="OPTIONS Set Access-Control-Allow-Methods for response" preCondition="OPTIONS" patternSyntax="Wildcard">
                    <match serverVariable="RESPONSE_Access-Control-Allow-Methods" pattern="*" />
                    <action type="Rewrite" value="OPTIONS,GET,POST,PATCH,PUT,DELETE" />
                </rule>
                <rule name="OPTIONS Set Access-Control-Allow-Origin for response" preCondition="OPTIONS" patternSyntax="Wildcard">
                    <match serverVariable="RESPONSE_Access-Control-Allow-Origin" pattern="*" />
                    <action type="Rewrite" value="*" />
                </rule>
                <rule name="OPTIONS Set Access-Control-Allow-Headers for response" preCondition="OPTIONS" patternSyntax="Wildcard">
                    <match serverVariable="RESPONSE_Access-Control-Allow-Headers" pattern="*" />
                    <action type="Rewrite" value="*" />
                </rule>
                <rule name="OPTIONS Set Access-Control-Max-Age for response" preCondition="OPTIONS" patternSyntax="Wildcard">
                    <match serverVariable="RESPONSE_Access-Control-Max-Age" pattern="*" />
                    <action type="Rewrite" value="3600" />
                </rule>
                <preConditions>
                    <preCondition name="OPTIONS" patternSyntax="Wildcard">
                        <add input="{REQUEST_METHOD}" pattern="OPTIONS" />
                    </preCondition>
                </preConditions>
            </outboundRules>
        </rewrite>
	</system.webServer>
</configuration>