Replace table field's default value in a Hosted Feature Service?

[Wolfgang_Grunberg_AZ_DFFM]

How do I change the default value for a table field (has a domain) in an existing Hosted Feature Service?

• AGOL's Data>>Fields>>Details interface allows me to edit domain entries (very nice) but I can't change the Default Value.
• ArcPro's "Assign Default To Field tool" gives me a "000664: Invalid input: This type of dataset is not supported" error. 

The lookup table is in a Many-to-1 relationship with a point layer in the same Hosted Feature Service.

Thank you for your time!

[MobiusSnake]

I believe you need to use the administrative REST API ("Update definition") to do this.  This call is also available in the ArcGIS API for Python.