Husband did it for me last night. It is 'processing'. He had to write me a sponsor letter as all the money is in his bank account. Also added scan of marriage certificate.
It varies so much. We were going to do it as older nomads but decided to join a combat school (paid for tuition). However we had a biz pack ready. It included biz registration, where it is incorporated (ours was Australia) Certificate of employment/contract, engagement letter and a letter we wrote saying we had permission to work remotely. DM me for copies. Husband has them.