If you have the chrome extension installed and you are logged in you can right click somewhere in chrome. In the appearing menu select “link.fish”. One of the points in there will be “Set active collection” where you can choose which one should be active.
The collection which is set there will be the one new pages will get saved to. Depending on that will also the link.fish-icon change when you are on a page which got already saved in the selected collection.
By default, it is set to “shift” and “right mouse button”. However, that can get changed in the plugin settings. Simply click with the right mouse button on the little fish next to the address bar and select “Options”. On the appearing page, you can then select the key and button you want to use instead.
There are actually multiple possibilities. If you are already logged in app.link.fish it will log you in automatically.
If thats, not the case you can click on the small fish icon next to your address bar like if you want to bookmark the page. It will then display you the login form first.
You can download it directly from the Chrome web store here: