Signing w-9 Tax form

I just started to upload photos for approval to sell as stock.  I was directed to sign the w-9 tax form.  I singed up for the free trial of Adobe Sign to do it.  I also have the most updated Adobe Acrobat Reader.  I'm using a Mac OS10.14.6.  When I put in my username and password for Adobe Sign and submit to loging, it just stops working, nothing else shows up, not even and error.  I got the same result from my ipad 7.  I can log directly into Adobe Sign, so i know the username and password are correct.

Pls Help..