The "Interface Vlan" endpoint allows you change the untagged (ie. access) vlan of an interface (if your token allows it). You need to POST the proper vlan parameter.
Note: you token needs to allow access to the interface and to the new vlan!
Here is an example of a call to the "Interface Vlan" endpoint, disabling the interface:
http --form POST http://localhost:8000/api/switches/35/272/interface/3/vlan/ 'Authorization: Token ***34b' vlan=500
It returns an HTTP 200 OK with a result field, or an HTTP 4xx error code with a reason.
On success:
HTTP/1.1 200 OK
...
{
"result": "Interface GigabitEthernet1/0/3 changed to vlan 500"
}
and on failure:
HTTP/1.1 403 Forbidden
...
{
"reason": "You can not manage this interface!"
}