That is not true - donations are not usually considered profit, at least in Germany. They occupy a bit a weird middle ground. They may count as income, but for example donations we receive for the open source projects that our company runs are VAT exempt. However, it must be true donations and not provide material benefit - if the donations provide any substantial benefit (priority when considering features or bug fixes, access to special features, …), then it‘s no longer donations but services. Things like a mention on a supporter page, occasional swag and stickers, … are usually fine.
As always, talks to your tax accountant about your specific case, this is not legal or tax advice, …