As one of the creators, I can recommmend https://kreya.app. It is not open source (like Postman), but has a strong focus on privacy and also stores the data locally.
As it has more powerful features (IMO) than most alternatives listed here, I am a little disappointed that it isn't mentioned more often.
As it has more powerful features (IMO) than most alternatives listed here, I am a little disappointed that it isn't mentioned more often.