Shutter opening command

Hello everyone
I am updating the metadata on OpenHab 2.4, I have read the procedures in the various posts, but I have not found if it is possible to control the shutters from Google Assistant communicating the opening or closing in percentage Ex: open / close bathroom shutter at 50%
At the moment I have updated this and it only works fully closed or fully opened.

Switch mqttSonoff5_1     "SOnOff 5-1 [%s]"                 							           											 {mqtt=">[mosquitto:cmnd/shelly-bagno/POWER1:command:*:${command}],<[mosquitto:stat/shelly-bagno/POWER1:state:REGEX((.*))]"}
Switch mqttSonoff5_2     "SOnOff 5-2 [%s]"               						             			    							     {mqtt=">[mosquitto:cmnd/shelly-bagno/POWER2:command:*:${command}],<[mosquitto:stat/shelly-bagno/POWER2:state:REGEX((.*))]"}
String mqttSonoff5lwt    "SOnOff bagno   [%s]"                                           										 {mqtt="<[mosquitto:tele/shelly-bagno/LWT:state:default]"}
String mqttSonoff5state  "WIFI tapparella bagno [JSONPATH($.Wifi.RSSI):%s%%]" <network> 		 (wifi)          {mqtt="<[mosquitto:tele/shelly-bagno/STATE:state:default]",autoupdate="false"}
Rollershutter Sonoff5    "Bagno   [%d%%]"                                            	  		 (tapparelle)    {autoupdate="false"}
Switch tapparella_bagno	 "tapparella bagno "             			 	  		       <rollershutter> (tapparelle)    {ga="Shutter" }

Thanks in advance

Your GA metadata data is attached to a switch, which only offers ON/OFF. Per the documentation:

Blinds and similar devices should always use the Rollershutter item type for proper functionallity.