How to build links for a multi-language website?

How do you manage link building for a multi-language website and how to manage internal linking for passing link juice?
Is putting a button for switching the language an effective way for passing the link juice obtained with a backlink for the first language page version to the same page with the other languages a good pratice of internal linking, like an internal link?

Its very important to get link from the specific language website for getting good and stable result, apoart from that you can also try PPT posting , and other link building activities that we are already using for english lanugage website SEO.

add 2 projects. issue a version in the main language, and then copy the pages

Create links that point to the specific page for each language, ensuring that the language is specified in the URL. Additionally, use hreflang to specify the language of each page and ensure the correct version is served to users.