Why do it the hard way when you can do it the easy way? Open Blogger -> Layout tab -> edit Pages gadget -> start typing: title or URL and Blogger will suggest you pages that are already published. You can also add links manually, both internal and external.

Then you can go to the theme editor and you will see that it works in a bit different than in your code. There should be link0, link1, etc.

{"link0":{"href":"https://bio.weblove.pl/","position":0,"title":"Blogger Help"},"link1":{"href":"","position":1,"title":""},"link2":{"href":"","position":2,"title":""}}