When logged into your P21 middleware you will be shown something along the lines of the following:
Upon selecting "API Console" you will be presented with the list of available P21 API 'users' that can be used to access the data available in the "API Scope":
The SARA Collect sync currently needs the following permissions in order to properly run: /data/erp/views/v1
This is the base level API connection which allows read only access to the data, according to epicors' documentation which can be found at (API Reference Data Services Data Service Documentation)