You will probably not find an established P2E game that you can play for free and still earn. You'll be required to spend at some point so you can upgrade your weapons or skills and be able to actually compete with other players. Your best bet is looking for new games but the catch is that you'll never really know if it's legit until you try it.
Not unless you'll be a part of their campaign before you'll get better benefits on P2E games. This is one of the reasons why most influencers try their hardest to promote the site or app they are using.
I have also once participated a P2E game by being a discord moderator and earn some specil perks. To be honest nowadays its hard to participate in P2E games if you don't have anything to contribute on their platform, some requires tremendous effort just to receive benefits while some just need enough cash to receive special bonuses like a VIP.