At the time of initiating a payment if you see “signature mismatch” error, it could be due to any of the two reasons -
You have entered incorrect credentials (appId/secret key) - for test or production
The parameters (orderId, order amount etc) are incorrect or missing
Whenever you encounter a signature mismatch error go back to the payment page and follow the below steps to debug this further. See the video below for more detail.
Right click on the page and select inspect
Go to the Network tab and check both the options Preserve log and Disable cache
Make sure to clear the network activity section before proceeding
Click on Payment button(to make the payment)
Once you click on the payment button, you will see a submit document being added to the network activity area
Click on submit (doc) and scroll down, you will see the form data which specifies your appId, orderId, signature etc
Copy the parameter values and use the tool below, depending on the integration mode you are using.
You should verify that signature you have generated matches with the one being generated by the above tool.