Create a Magento API user with admin access
The first step is to create a Magento SOAP/XML-RPC user with admin access.

Create an API role
Create a SOAP/XML-RPC Role with access = All
- In the System menu, select Web Service > SOAP/XML-RPC – Roles.
- If an “All access” role does not already exist, create one by selecting Add New Role.
- Give the role a name. (For example, “Admin”)
- In the Role Resources tab, select All in the Resource Access dropdown.
- Save the role.
Create an API user
Finally, create a SOAP/XML-RPC User with that role:
- In the System menu, select Web Service > SOAP/XML-RPC – Users.
- Selecting Add New User.
- Fill in the required information and remember the user name and API key that you enter.
- Give this API user the “All access” role that you just created earlier.
- Save the new user.

Add the Magento store to OMS
- Login to your OMS account
- In Add/Edit Platform > Click on Add New Platform button
- Select Magento from the dropdown.
- In the API access section, complete the fields as follows:
- Display Name: Give display name.
- API URL: Your website URL. For example : https://www.mymagentostore.com/
- API login: This is the API User Name for the Magento API user that we have created
- API password: This is the API Key that was used earlier in the creation of the Magento API user
