Uploading data points to Digi Remote Manager requires an Internet connection. XBee3 Zigbee does not have an Internet connection - it speaks Zigbee.
In order to transmit data from an XBee3 Zigbee to Digi Remote Manager, you should use our XBee Gateway (https://www.digi.com/products/networking/gateways/xbee-gateway), XBee Industrial Gateway (https://www.digi.com/products/networking/gateways/xbee-industrial-gateway), or even something like the ConnectPort X4 (https://www.digi.com/products/networking/gateways/connectportx4).
These products support Python programmability.
Moreover, the XBee Gateway and XBee Industrial Gateway ship out-of-the-box running a Python application that uploads Digital I/O and Analog I/O readings received from XBees to Digi Remote Manager. This application is open-source (https://github.com/digidotcom/xbgw-app), and you could extend it to communicate with a MicroPython application like you want.