Look for the sign button rather than a graphic, it works fine

There is a petition site here in the UK called 38 degrees. Until a couple of months ago, there was no problem clicking on links to sign petitions. They have changed the link to a graphic. What it says is graphic wrecked angle contains link. I am unable to find a way to activate these links using NVDA which is my only screen reader..

Sent from Mail for Windows 10