Adding client profile to Authorize.net error message

Can you let me know if you have time to look at this or maybe you just know the answer from previous experience:

I'm trying to add customer profile to authorize.net with a form that clients fill to add their credit card. It seems to almost work. However, I am getting an error message from Authorize about the credentials, even though I know I have the correct credentials because it's the ones we use in our shopping cart page which work all the time and the last they were updated was in 2019.

Error message is:

"Create Customer Payment Profile: ERROR Invalid response Response : E00007 User authentication failed due to invalid authentication values."

I attached the file I have (without the authentication numbers). I am still searching for answers but spending too much time on this. Maybe it has to do with the PHP code (that I don't fully understand) and you can spot it.

Thank you.

I'd probably have to actively debug it in a screen share to get anywhere. The error means the transaction key is not recognized, so it either has a typo or isn't set correctly somehow.

There's no typo so it's probably not set correctly then. It's in the file I sent you. If it's not something obvious to you, I'll try to contact you at some point to get tech support on it. Thanks for your help.

Yeah I've never used that library, so it isn't obvious to me. It could be your authorize.net account isn't configured to allow that particular functionality and there is nothing wrong with the code at all.