To disable the payment method only for the frontend and keep it enable for the backend, Select the payment method under the configuration Store ⟶ Configuration ⟶ Magediary ⟶ Payment & Shipping Hider ⟶ Payment Methods Reference ...
To disable the shipping method only for the frontend and keep it enable for the backend, Select the shipping method under the configuration Store ⟶ Configuration ⟶ Magediary ⟶ Payment & Shipping Hider ⟶ Shipping Methods Reference ...