Unlocking characters in Genshin Impact requires for you to acquire wishes. These wishes are initially shown to you when you first go through the story before visiting the various temples and challenges surrounding Mondstadt. The first wish you use in the game is given to you at the start of the game, for free. However, afterword, you still need to use this method to unlock other characters, but it does come with a price.
To receive additional wishes in Genshin Impact, you need to use Acquaint Fate. It’s a premium currency in the game that you can seldom acquire by playing the game. There are a handful of Adventurer’s Rank rewards that give you this currency. Otherwise, you need to directly pay for it using the Primogem you acquire by going through various achievements and steps in the game. It costs 160 Primogem to purchase a single piece of Acquaint Fate or Intertwined Fate. Both of them are a premium currency.
If you want more Primogems to purchase additional Acquaint Fate or Intertwined Fate, you can buy them in the Shop using real-world money. It’s a faster way to receive additional characters and equipment than naturally playing through Genshin Impact.
When you have all of the premium currency, you want to buy on your profile, return to the main menu and go down to the wish category. It should be the third option. When you pull up the wishes option, you should see all of the available options. For every wish you want to call for, it costs one Acquaint Fate or Intertwined Fate. However, some of the purchasable options have increased chances if you go for a larger bundle. For example, you have a guaranteed chance of receiving a four-star character or weapon by using 10 Acquaint Fate. It’s a better deal, but it means you may have to wait longer to purchase that bundle.