I haven't tried to participate in the Quebec lottery, but you might try calling one of the fly shops in Montreal to ask. That's how I would start, anyway. I imagine they get asked such questions a lot.
You might also want to ask at one of this forum's sister websites, the Salmon Atlas forum: Salmon Fishing Forums . It's not as active as this site, but the people there are hardcore salmon anglers. You can use the same username and password that you use here.
Matane river has sectors where you can make fishing without participate to a draw you just buy your access to the river and fish all day ,the river has also sectors for fishermans who has been picked to winter draw or 48 hours before the fishing day , others river Matapédia ,Mitis are similar to Matane for informations Matane river in season from june 15 to september 30 telephone 418-562-7006 You'r Welcome
For participate to the lottery for Matane the cost is three dollars for one card of draw it's for 48 hours before the fishing day you may also participate to the winter draw look my previous post for informations (tel number)
I've read about the lottery draws for salmon in Quebec and find it very confusing. I'd love to try the Gaspe area for salmon but with the reg's and COVID, I think I'll pass. It seems more like you'd need a hire a guide to help get you thru all the red tape to get started..