[SOLVED] JSON Path "(DWD) Deutscher Wetterdienst Pollenflug " pollen flying

here is my final CONFIG:

Pollen.items

String	DWD_Pollen_last_update					"letzte Aktualisierung [%s]"		<time>				{http="<[cacheDWD_Pollen:600000:JSONPATH($.last_update)]" }

//--> Gräser
String		DWD_Pollen__Graeser_today			"heute [MAP(Pollen.map):%s]"		<graeser>			{http="<[cacheDWD_Pollen:600000:JSONPATH($.content[?(@.partregion_id==123)].Pollen.Graeser.today)]" }
String		DWD_Pollen_Graeser_tomorrow			"morgen [MAP(Pollen.map):%s]"		<graeser>			{http="<[cacheDWD_Pollen:600000:JSONPATH($.content[?(@.partregion_id==123)].Pollen.Graeser.tomorrow)]" }
String		DWD_Pollen__Graeser_dayafter_to		"übermorgen [MAP(Pollen.map):%s]"	<graeser>			{http="<[cacheDWD_Pollen:600000:JSONPATH($.content[?(@.partregion_id==123)].Pollen.Graeser.dayafter_to)]" }

//--> Birke
String		DWD_Pollen__Birke_today				"heute [MAP(Pollen.map):%s]"		<birke>				{http="<[cacheDWD_Pollen:600000:JSONPATH($.content[?(@.partregion_id==123)].Pollen.Birke.today)]" }
String		DWD_Pollen_Birke_tomorrow			"morgen [MAP(Pollen.map):%s]"		<birke>				{http="<[cacheDWD_Pollen:600000:JSONPATH($.content[?(@.partregion_id==123)].Pollen.Birke.tomorrow)]" }
String		DWD_Pollen__Birke_dayafter_to		"übermorgen [MAP(Pollen.map):%s]"	<birke>				{http="<[cacheDWD_Pollen:600000:JSONPATH($.content[?(@.partregion_id==123)].Pollen.Birke.dayafter_to)]" }


http.cfg --> The values by DWD will be updated every Day at 11am

http:cacheDWD_Pollen.url=https://opendata.dwd.de/climate_environment/health/alerts/s31fg.json
http:cacheDWD_Pollen.updateInterval=3600000

Pollen.map

-1=keine Daten
0=keine (0)
0-1=keine bis gering (0-1)
1-2=gering bis mittel (1-2)
2=mittel (2)
2-3=mittel bis hoch (2-3)
3=hoch (3)

sitemap

Frame label="Gräser (Vorhersage)"	visibility=[DWDSelectedSite==7] {
				Text item=DWD_Pollen__Graeser_today			valuecolor=["0"="#008000", "0-1"="#00ff00", "1"="#ffff00", "1-2"="#ff0000", "2"="#ffa500", "2-3"="#ff0000" , "3"="#ff0000"]
				Text item=DWD_Pollen_Graeser_tomorrow		valuecolor=["0"="#008000", "0-1"="#00ff00", "1"="#ffff00", "1-2"="#ff0000", "2"="#ffa500", "2-3"="#ff0000" , "3"="#ff0000"]
				Text item=DWD_Pollen__Graeser_dayafter_to	valuecolor=["0"="#008000", "0-1"="#00ff00", "1"="#ffff00", "1-2"="#ff0000", "2"="#ffa500", "2-3"="#ff0000" , "3"="#ff0000"]	visibility=[DWD_Pollen__Graeser_dayafter_to !="-1"]
			}
			Frame label="Birke (Vorhersage)"		visibility=[DWDSelectedSite==7] {
				Text item=DWD_Pollen__Birke_today			valuecolor=["0"="#008000", "0-1"="#00ff00", "1"="#ffff00", "1-2"="#ff0000", "2"="#ffa500", "2-3"="#ff0000" , "3"="#ff0000"]
				Text item=DWD_Pollen_Birke_tomorrow			valuecolor=["0"="#008000", "0-1"="#00ff00", "1"="#ffff00", "1-2"="#ff0000", "2"="#ffa500", "2-3"="#ff0000" , "3"="#ff0000"]
				Text item=DWD_Pollen__Birke_dayafter_to		valuecolor=["0"="#008000", "0-1"="#00ff00", "1"="#ffff00", "1-2"="#ff0000", "2"="#ffa500", "2-3"="#ff0000" , "3"="#ff0000"]	visibility=[DWD_Pollen__Birke_dayafter_to !="-1"]
			}
			Frame label=" "		visibility=[DWDSelectedSite==7] {
				Text item=DWD_Pollen_last_update
			}

Only one thing I would like to improve.
I would like to change the “last update” item as a String to DateTime.
Unfortunately, I do not know exactly how I should do that.

Thanks a lot to @vzorglub and @Udo_Hartmann