Usually it is as simple as being connected through eduroam (the university wifi) or VPNing into the university network. Sometimes you have to log in to the university library portal and get it through there. Some journals want you to create accounts to access, and don't let you download, only read in the webviewer (without highlights or annotations of course).

Either you need to log in 5o your universities bespoke portal that aggregates your providers, or you need to do some weird third party registration, and navigate a bunch of login flows on the slowest websites in eternity. Closest comparison is imagine you want to a watch a show on your laptop but you don't know if it's on netflix, prime or Disney.