the client want to set new payment method and the payment method provider has their documentation https://weaccept.co/docs/guide/online-guide/ (https://weaccept.co/docs/guide/online-guide/)
but now on payment methods lists there is no way to add new pamyment method type
what if i do not want to use any of these preconfigured payment methods and add new method and configure it
Each gateway need own plugin
You have to create a payment plugin or see with a developer to do it for you(better someone having experience with Virtuemart plugins). You can find some developer in the forum here that answered on many threads, to have chance, he code right the plugin.