How can a Customer make Payment if Admin has created Order on Behalf of Customer?
https://docs.magento.com/user-guide/v2.3/customers/customer-account-create-order.html
How can a Customer make Payment if Admin has created Order on Behalf of Customer?
https://docs.magento.com/user-guide/v2.3/customers/customer-account-create-order.html
In a default Magento install, you can use several approaches to achieve this by using some of the offline payment methods:
It really depends on what suits your business needs, what I listed above are just the cleanest ways to achieve this without having the client tell the admin sensitive data like credit card data, checks data, or other stuff. I would say these are the safest payment methods in your scenario.