Vietnam form e check third party invoice - mainland company

This is Xinxinyuan Xiaoou, Sichuan Province. We are a mainland company. Form e certificate of origin can be handled by an agent. The first item shows the name of the agent company, and then the seventh column shows our bill of lading shipper, right? I checked online to check the third party invoice, right? I asked other agents before that the mainland companies can not choose the third-party invoice. I think you can handle it on the website. If so, how do you need to handle it? I would like to ask again, because we have not done this kind of form e before. We are a mainland company. Would there be any problem with the origin of the invoice made by the third party? Will the customs check? In case there is a problem at that time, what should be done if the Vietnamese customers cannot use the form e?