The in-game currency of PUBG Mobile, i.e. UC or Unknown Cash, is quite expensive. UC is used to purchase various items such as skins and other cosmetics from the in-game store. Since many gamers cannot afford to buy UC, they often look for ways to get the UC for free.
The only way of getting UC initially for free in Season 13 or in any other season is by using GPT sites and apps.
GPT (Get paid to) sites are websites where the users can complete offers like answers surveys, completing quizzes to receive points with which they can claim rewards.
On that note, the various GPT sites one can use to get an upper hand in PUBG Mobile are -
Grab Points is a GPT site where the user can complete various offers to get rewards. One will get rewarded for completing offers like surveys and a lot more. These points can be used to redeem PayPal cash, Flipkart gift vouchers, which in turn, can be used to purchase UC in the PUBG Mobile game.
Prize Rebel is also a GPT site similar to GrabPoints. Completing the offers will fetch the users with points that can be used to redeem the rewards. Like GrabPoints, users can redeem Paypal cash, Flipkart Gift Vouchers with which UC can be purchased in the PUBG Mobile game.
Google Opinion Rewards
Google Opinion Rewards is an app developed by Google. This app rewards the user with play credit for completing surveys. With these play credits, players can purchase UC.
There is no other way to get UC in PUBG Mobile for free initially. The UC generator is an illegal way to get UC and can lead to permanent bans as it is a violation of terms of service as laid out by Tencent Games.
These UC can later be used in Bonus Challenges, which provides players with a system to earn UC by completing challenges in the PUBG Mobile game. To play bonus challenges, players require a bonus voucher which can be purchased for 10 UC.