Problem with Paypal paiment on shopify

[zoyott]

I am trying to make PayPal Payflow Pro work on shopify store to get paiment by credit cards.

when I test a paiement,  I got an error with message:  INVALID VENDOR ACCOUNT.

I did some search and apparently I may have entered the wrong credentials.

There are some credentials that I don't really understand where they are such as:

PARTNER

VENDOR

what is Merchant Login / Vendor in shopify

where can I find these two credentials?  if someone can provide screenshots of where these are, i will be so grateful.

Thanks

[namtel]

I am unable to process any payment through paypal on my website. I think the error is because of the API Signature. Paypal provides 3 API credentials. 

1. API Username
2. API Password
3. Signature

In shopify payments settings >> Accept payment through credit card >> PayPal Payflow Pro

There are 4 blanks for credentials

1. Merchant Login / Vendor - This is where I enter my API Username
2. Password - This is where I entered API Password
3. Partner - I don't know what this is about
4. User (Optional)

Ther is no space provided to enter the "signature" from my API credentials.

How do I fix this and accept payments through PayPal Payflow Pro?