There are a few different ways to lock form fields in Adobe:
1. Use the "Protect Document" feature. This will allow you to set a password for the document, and restrict editing of specific form fields.
2. Use the "Lock" button in the Forms panel. This will lock all form fields in the document, and they cannot be edited until the lock is removed.
3. Use JavaScript to Lock Form Fields. You can add a JavaScript action to a field that will make it read-only or prevent it from being changed.