Just to be safe, remember to make an alt account and run R5Reloaded ONLY with your alt.
Use a legit email (like gmail), not a temp mail.
Origin will quickly ban your account if it detects you've used a temp mail.
After you log in, you need to add Apex Legends to your library:
Once you do that, it's recommended to disable auto-updates.
To do so go to Origin->Application Settings.
Find the Client update section, and disable Automatic game updates.
After you are done with everything, leave origin in the background and open the game with Run R5 Reloaded.exe.
If for some reason the game still doesn't boot up, visit our Discord and ask us in the #questions channel.