Another tip is if you use an auto-refresh extension on your browser and target a retailer's page like Amazon and set it up so it automatically notifies you if there's a change to the content of the page, e.g."Out of stock" text changing to "In stock" or whatever labels the retailer uses on the page. I've used this one https://autorefresh.io/ in the past and found out to be a bit quicker than Stockinformer as there's less latency between the change and the notification being sent out.
Or just wait a couple months? People out here acting like it's life or death that they get it right NOW
I'm not after one myself, but sharing knowledge of the methods I used to purchase a Nintendo Switch back in April last year to kill some lockdown boredom. Of course I could have waited until September/October when stocks were better, but where's the fun in that? And it currently looks like stock has dried up for that too.