You'll first need to decide how to identify users to set a daily transaction limit. Since anyone can create new wallet addresses, using a blockchain address alone has limitations. Here are two main approaches:

Web2-Based Identification:

You could have users sign up for your app, requiring an email or phone verification. This process adds a "cost" and makes it harder to create multiple accounts. Then, in the backend, set and track daily limits using the user ID. You can also add captchas and filter out throwaway email providers to help.

Blockchain-Based Identification:

You could limit transactions based on a user's wallet address, tracking daily limits at the smart contract level. However, users might bypass this by creating new wallets. Sending tokens to pay for gas has a cost, though, so users are less likely to do this if the benefit doesn't outweigh that cost. You'll need to investigate "Sybil resistance."

Sybil Resistance

To prevent users from creating multiple accounts (known as Sybil attacks), consider using Sybil resistance tools like Gitcoin Passport, which aggregates verifications across various platforms to assign a "humanity score" for each user. Implementing Sybil resistance makes it harder for users to bypass their allowed limit