Here are already collected certain points on the map for different blips. And in order not to waste valuable time searching for various coordinates, I have gathered here the main and additional points. You can also add something of your own.
Additional resources that I used: https://wiki.altv.mp/wiki/GTA:Blips https://altmp.github.io/altv-typings/classes/_alt_client_.blip.html#route
In order for markers to be displayed in the game you must add a request to the server side!!
Example:
alt.on('playerConnect', (player) => { const blip = ["MarketA","MarketB",......]; for (let blips of blip) { alt.emitClient(player, blips); } });