If you are using a new device, or made a new account with your cryptowallet, you may need to "restore" your wallet. The restoration process depends on which cryptowallet you are using, but nearly all restoration processes require a private key.
A private key is a special secret phrase that can be used to restore your wallet, or access your wallet should you forget your password.
Trust Wallet Restoration: https://help.trustwallet.com/hc/en-us/sections/360000144094-Restore-Import-a-wallet
Cool Wallet Restoration: https://help.coolwallet.io/article/58-can-I-recover-my-coolwallet-s-seed-to-another-wallet