How do I attach/embed the logo or other images in the emails?

I have a logo that I want to embed at the top of all my emails so it shows up without clicking “download images”. How do I do that?
Including them via src url, base64, or inline svg do not work in most email clients like Gmail. I want to be able to upload them and then refer to them by the standard cid method. I’m fine rebuilding all of this if I need to.