Is the word `credentials` singular or plural?

I know that the word credentials is the plural form of credential.

And I'm referring to a single pair of username and password as credentials. Oxford dictionary also suggests that the word credentials is widely used over the word credential. Taking all these into account,

Which of the following is right?

• The credentials that you have provided are invalid.
• The credentials that you have provided is invalid.

EDIT: I'm referring to a single pair of username and password as credentials, That's what has made me ask this question.

According to Merriam-Webster:
Credentials is the plural of the word credential.

It is grammatically correct to say the first option:
The credentials that you have provided are invalid.

Credentials is used over its singular form credential but it is still a plural noun.