For various purposes you might want to enable or disable your android inbuilt SIP phone with tasker. E.g. in my case I only have SIP enabled if the battery is above 78% or the phone is charging.

• App Tasker (sorry no FDroid)
• Additional permissions for Tasker
  • android.permission.WRITE_SETTINGS
  • android.permission.WRITE_SECURE_SETTINGS

adb shell pm grant net.dinglisch.android.taskerm android.permission.WRITE_SETTINGS
adb shell pm grant net.dinglisch.android.taskerm android.permission.WRITE_SECURE_SETTINGS

It simply sets sip_receive_calls in System Secure Settings to 0 or 1.

As Tasker DataURIs:

• Tasker Task SIPcalls ON
• Tasker Task SIPcalls OFF

As compressed XML Tasks: Tasker Tasks SIP on/off

None