Ask Lemmy

On your home instance: https://legal.lemmy.world/tos/#70-advertising

7.0 Advertising

Lemmy.world is a free service, funded by donations and run by volunteers for the benefit of its users. As such, it is not intended to be used as a marketing channel for extensive commercial advertising or product promotion. Promoting or recommending products and services is generally allowed provided that the following criteria are met:

1. It is relevant to the community where it is posted.
2. It offers something of value to our users.
3. It is created for community engagement rather than being a one-way message directed at users.

Users or communities which primarily promote paid products or services, with little other engagement on Lemmy, may have their content removed and may be banned. This includes personal promotion such as a GoFundMe drive, OnlyFans page, or blog.

I can only speak for my own (non-Lemmy.World) instance, but I do not allow any kind of fundraising campaigns. They're too difficult to verify they're not fraud, and allowing any just opens the floodgates to having to verify each one.

The !mutual_aid@hexbear.net community seems similar to what you're asking for. I'm not sure if there are more similar comms on other instances but that's just the one I know of.

Depends on the community and instance you post it on, different instances may have different rules