You have the option to buy Certification Credits with fiat using USDN.
Certification Credits will allow you to use all the Certification features without the need to hold any token/crypto in your account, instead, a number of credit will be associated to your account and deducted after each Certification.
The credits associated to your account are displayed at the top of the webapp:
To buy credit with USDN, you need to click on the "USDN > SIGN" button on the left sidebar:
This will open a popin with the USND > SIGN convert form.
USDN is a stablecoin and is therefore always valued at the price of 1$, SIGN Certifications are priced at 0.5$, so the conversion is really easy. You can convert any USDN to SIGN Credit by entering the amount of USDN to convert, this amount needs to be a multiple of 0.5:
Click confirm and the Waves Signer popin will open with the transaction details, verify that everything is correct and click "Confirm":
Once the transaction is confirmed, you will receive a confirmation message and your account credits will be credited: