• Download the module and place the module in apps folder.
• Install the python dependencies.
• Install this module in your Odoo instance.
• Open Website > Configuration > Payment Acquirers and open acquirers
• Fill the API keys and credentials. (You will these keys from your mollie dashboard)
• Click on Mollie Payment Methods tab and click on sync payment method button.
• That's it you are ready to accept payments.

You will need two Python packages for using this application. You can install both these requirements by running the following command:

pip3 install -r requirements.txt

Learn more about it: https://apps.odoo.com/apps/modules/14.0/payment_mollie_official/