If you are trying to get cryptocurrency without investment, you can try to improve your skills in the field of programming and try your skills in the field of blockchain, cryptocurrency, and various other jobs related to it. Or you can try your luck on this forum by developing your account well and entering a signature that has Bitcoin rewards, that might be your way to get cryptocurrency without the need for investment. It's a little difficult, but you have to try.
Using your skills to earn bitcoin is selling a service and so is getting paid through signature campaigns. Literally speaking, there is not such thing as earning without an investment, these things require your skills and time as the investment and the earning as the return.
OP should learn that for any type of coin to be earned, there needs to be some contribution from their end or some risk taking involved. Free money does not exist and only a lure by scammers.
Still dont get why people dont focus on getting a stable job first and then add bitcoin earning as side earning to eventually grow it.