Hi,
Under the plugin’s General settings set the Amount limits as Minimum and Amount types as Sum.
Then go to the Payment gateways tab and make sure you Enable the section and add a minimum amount for the relevant payment gateway. Also set the priority lower to 10 for example.
Since most of the time the payment gateways are selected on the checkout page, under the General tab make sure, the Block checkout page option is disabled.
Also under the Messages tab enable the Checkout notices and set the relevant position on the checkout page for the message.
In the amounts tab, you can leave it as zero.