Re: Sharepoint folder share approval on behalf of external member
@DTL747 the Send HTTP Request to SharePoint action needs to be configured differently
Add action "Get file properties" just before "Send an HTTP request to SharePoint" action and configure it as follows:

Then configure Send HTTP request to SharePoint action as follows,

Below is the Uri to be used on this action, replace
_api/web/GetFileByUrl(@v)/ListItemAllFields/ShareLink?@v='@{outputs('Get_file_properties')?['body/{FullPath}']}'
Configure below json payload in Body parameter
{
"request":{
"createLink":true,
"settings":{
"linkKind":7,
"expiration":null,
"role":2,
"restrictShareMembership":true,
"updatePassword":false,
"password":""
},
"peoplePickerInput":"[{\"Key\":\"@{triggerBody()['text']}\",\"DisplayText\":\"@{triggerBody()['text']}\",\"IsResolved\":true,\"Description\":\"@{triggerBody()['text']}\",\"EntityType\":\"\",\"EntityData\":{\"SPUserID\":\"@{triggerBody()['text']}\",\"Email\":\"@{triggerBody()['text']}\",\"IsBlocked\":\"False\",\"PrincipalType\":\"UNVALIDATED_EMAIL_ADDRESS\",\"AccountName\":\"@{triggerBody()['text']}\",\"SIPAddress\":\"@{triggerBody()['text']}\",\"IsBlockedOnODB\":\"False\"},\"MultipleMatches\":[],\"ProviderName\":\"\",\"ProviderDisplayName\":\"\"}]",
"emailData":{
"body":"",
"subject":""
}
}
}