I double and triple checked that I entered my Client and Secret keys correctly. Copy/pasted them from Twitter. Created a new pair on Twitter, which I then copy/pasted again, and time and time again I get this same error when trying to authorise the connection to Twitter.
Turns out you need to complete the following: https://www.make.com/en/help/app/twitter#create-custom-app-and-client-credentials-in-twitter
And then use the OAuth API key and secret key. Not the default one that Twitter provides.
Great job figuring out your struggle! We love to see Makers improving their Make skills. clap
Thank you very much for sharing the additional details with us. We appreciate it so much.