Why am I getting a "client authentication" error on my PayPal form?

I've talked to paypal, and been walked through their system to integrate.  I copied and pasted the client id and secret so no spaces or extra/mistyped letters.  When I sent the form to myself and tried it, I deleted everything, went through your instructions and followed them and then I sent it to myself again and got the same error message.  so what to do now?  Please help.

This seems like a duplicated thread, we already replied back to you here: https://www.jotform.com/answers/1805798

Please kindly follow up this on that thread. 

Thanks.