The private key signifies proof of your ownership over a wallet address and should NEVER be disclosed, exposed, or shared to anyone whether online or offline as doing so might lead to loss of funds. It should be stored somewhere safe (preferably offline on a piece of paper) where only you would know. Please take note that if a private key is lost, there is no way to either recover it or to regenerate it.
However, aside from the private key, there are also other ways you can use to import your wallet address and ultimately recover the tokens in them.
They are:
- Mnemonic phrase/seed phrase/recovery phrase
- an ordered list of 12 or 24 random individual words (read here)
- sometimes 13 or 25 with the additional word being a password that the owner personally sets
- Keystore/JSON file
- a file with an encrypted version of your address' private key (read here)
These are usually given to you upon creating a wallet address by the wallet service provider and they would normally remind you afterwards to always keep a backup of these somewhere personal and safe. If you have access to any of the above, you should be able to access/import your address easily. However, if you do not have any of these three, you might not be able to access your address again and recover your token back.
*Kindly take note that importing a wallet address by its private key or mnemonic phrase should be done as a last resort since doing so is prone to exposing them online. If you are urgently in need of the funds, it is recommended to transfer the funds to a newly created address after you have imported the existing address. Alternatively, if you are planning to just hold the funds, it is recommended to leave the tokens inside the address until you plan to use it.