By the way, in almost 100% of cases (the rest being just OA where the published version could be sent by anyone to anyone or something legally really dubious), the authors have a right to send their paper, even if it is published in a paywalled journal. Basically, the only thing the journal has a right to for subscription-based (aka those that cost $35) articles is content plus page layout. If the authors have the exact same text but formatted differently, they are free to distribute it wherever and however they want.

Preprint servers or lab/personal websites are best first choices for that.

edit: a small disclaimer on the exact same text meaning exact same text the authors provided; if the editor in the journal has corrected some typos and inserted a/the here or there (a common thing for non-natives to miss), then this becomes more of a grey area, because technically at this point it’s not a 100% authors’ text).