Thank you so much for your replies! I may have framed my question incorrectly. I understand we're not employees in sl. I am not looking for proof of income, but something to declare that I am a content creator in-world. I already have the income proof, and can state myself as self-employed. But it doesn't specify the essence of the work done in-world, it would merely be a self-declaration. I am in need for this because of an embassy paperwork, and looking for a way to be more specific about the kind of work done. (Also, I am not from the U.S.)
Anyway, I have figured its not easy to obtain and LL has not been of much help so far, because of clear reasons. I am just going ahead with financial documents I have with me, and hoping it suffices for this purpose.
Thank you again!