How Can a User Revoke or Modify a Token Allowance for a Specific Dapp?

A user can revoke or modify a token allowance by sending a new transaction on the blockchain. To revoke, the user submits an approve transaction for that specific token and dApp contract, setting the allowance amount to zero.

To modify it, they simply set a new, lower amount. Specialized tools and block explorers often provide a user-friendly interface to review all active allowances and create the necessary transactions to revoke them, simplifying the process.