How to add new key-value into an exists map

hi i have a record with 2 bins,uid(integer),data(map).at first i create a new record with default k1-value1 into the data,then how can i insert another k2-value2 into it?

the first k1-value1 must be reserved after new key-values inserted,or replaced when new k1-valueNew inserted

Currently, you have to read the map to the client, make changes and write map back to the server.

We are currently working on a map API that will allow map modifications on the server side. The release date has not yet been formalized.