firebase facebook Login: auth/internal-error - facebook

Question

I'm having issues with using the facebook login feature.
At the moment I have yet to deploy and am testing locally on my machine.
I've followed all the steps of:
1) Adding the facebook App ID and App Secret
2) changed the OAuth redirect URI to https://study-buddy-6646a.firebaseapp.com/__/auth/handler
However I am still getting the following error:
{"error":{"code":400,"message":"Error getting access token from
FACEBOOK, OAuth2 redirect uri is:
https://study-buddy-6646a.firebaseapp.com//auth/handler, response:
OAuth2TokenResponse{params:
error=OAuthException&error_description=Error%20validating%20client%20secret.,
httpMetadata: HttpMetadata{status=400, cachePolicy=NO_CACHE,
cacheDuration=null, cacheImmutable=false, staleWhileRevalidate=null,
filename=null, lastModified=null, headers=HTTP/1.1 200 OK\r\n\r\n,
cookieList=[]}}","errors":[{"message":"Error getting access token from
FACEBOOK, OAuth2 redirect uri is:
https://study-buddy-6646a.firebaseapp.com//auth/handler, response:
OAuth2TokenResponse{params:
error=OAuthException&error_description=Error%20validating%20client%20secret.,
httpMetadata: HttpMetadata{status=400, cachePolicy=NO_CACHE,
cacheDuration=null, cacheImmutable=false, staleWhileRevalidate=null,
filename=null, lastModified=null, headers=HTTP/1.1 200 OK\r\n\r\n,
cookieList=[]}}","domain":"global","reason":"invalid"}]}}
Any help would be greatly appreciated!