"When I try to login to the regular SMS production app with 7873, it does not work, but I can login to the online portal, so it is not a password problem"

1. "It doesn't work": how and what is the error?

2. "it is not a password problem": to login, you need the app client id, client secret, username, password AND extension number (if using the main company number). Any wrong the param will fail, NOT just the password.

Your 800 is a main company number and it's a TF number. TF number is not provisioned for SMS unless you create a request to enable for standard TF SMS feature.

thanks for the reply

1. the error when logging in with # 7873 is

 "error" : "invalid_grant",

  "errors" : [ {

    "errorCode" : "OAU-140",

    "message" : "Invalid resource owner credentials"

but I can login with that user/pass to ringcentral, I am extension 101 and have tried with and without the extension

2 I am using the client id, client secret, username, password AND extension number, just like I was in the sandbox, of course I am now using the production ID and Secret

    $SessionUser            =  "+15555557873"         

    $SessionPassword        =  "xxxxxxxxxxx"

    $ClientID               =  "xxxxxxxxxxxxx"     

    $ClientSecret           =  "hyGxxxxxxxxxnQ" 

    $sessionExtension       =  "101"

3. I created a request for the TF number
thanks

"just like I was in the sandbox", did you really change the client id and client secret for your production app? Did you change the server url to point to the production server? I fully trust this error "Invalid resource owner credentials" and I am 100% sure it's a mistake in your params.