I got the UK visa with combo card. webpage is clear enough, you just to to a USCIS center to give your fingerprint then ship it to your passport. Its so easy, you can get your pass back in 2 weeks

@Ivan b i was trying to apply for the UK visa but it asks if I am a permanent resident or hold a visa. my visa is long expired while i only have my EAD approved (not a combo). do you think i can put permanent resident on the form and apply using my EAD date as my resident approval date?

there is an other section in the form that you can say you’re not citizen neither permanent resident and write pending I-485 with a valid work authorization and travel document. but in you’re case if you don’t have a travel document how you will travel and come back to the US? @Fez H

@Ivan b My case is pending and I thought I may receive a decision or at least my AP anytime soon. that's why i thought i should apply for a visa ahead because as soon i get my AP or GC, i have to travel. i didn't see the other section you are mentioning, but will have another look