If you want to open all of your product's code, then you might want to use a public-private licensing model. https://indieopensource.com/public-private/users

Have a look at the Parity Public License and the Prosperity Public License. https://paritylicense.com/ https://prosperitylicense.com/

Those two licenses allow others to read, modify and redistribute your code. Parity requires that users open source their code, while Prosperity only allows non-commercial usage. If a potential customer doesn't want to be restricted by the public license you choose, they can instead buy a private license.

Also see License Zero's private license. https://licensezero.com/licenses/private