Oa is generally an internal system of a company. When the company's internal processes go through oa, they usually log in with a browser. However, oa of most companies will restrict browser login, so it is recommended to use ie in general. Oa is not particularly compatible with general browsers, and the load will not be very high. As for the login address, you can ask the personnel or colleagues in your company. Then enter the login page and enter your user name and password. You need to find personnel, and the general personnel will be assigned.