Unable to merge forms using Field Manager app due to login loop

I need to merge two forms into one.  How can I do this?  I tried the field manager app but it does not let me sign in, I am in a constant loop of putting in my username and password but then it doesn't let me go past that.  Or even if I can just add one form as the second page of the first form, is there a way to do this?

Our apologies for the inconvenience. There's been a conflict on the recent update of Google Chrome and Safari.

Kindly try Mozilla Firefox instead and let us know if you still require any assistance.