add translation key

src/Umbraco.Web.UI.Client/src/assets/lang/da-dk.ts

@@ -1829,7 +1829,9 @@ export default {
 		searchAllChildren: "Søg alle 'børn'",
 		languagesHelp: 'Tilføj sprog for at give brugerne adgang til at redigere',
 		sectionsHelp: 'Tilføj sektioner for at give brugerne adgang',
-		selectUserGroups: 'Vælg brugergrupper',
+		selectUserGroup: (multiple: boolean) => {
+			return multiple ? 'Vælg brugergrupper' : 'Vælg brugergruppe';
+		},
 		noStartNode: 'Ingen startnode valgt',
 		noStartNodes: 'Ingen startnoder valgt',
 		startnode: 'Indhold startnode',

src/Umbraco.Web.UI.Client/src/assets/lang/en-us.ts

@@ -1830,7 +1830,9 @@ export default {
 		languagesHelp: 'Limit the languages users have access to edit',
 		allowAccessToAllLanguages: 'Allow access to all languages',
 		sectionsHelp: 'Add sections to give users access',
-		selectUserGroups: 'Select user groups',
+		selectUserGroup: (multiple: boolean) => {
+			return multiple ? 'Select User Groups' : 'Select User Group';
+		},
 		noStartNode: 'No start node selected',
 		noStartNodes: 'No start nodes selected',
 		startnode: 'Content start node',

src/Umbraco.Web.UI.Client/src/packages/users/user-groups/modals/user-group-picker/user-group-picker-modal.element.ts

@@ -57,7 +57,7 @@ export class UmbUserGroupPickerModalElement extends UmbModalBaseElement<any, any
 
 	render() {
 		return html`
-			<umb-body-layout headline="Select user groups">
+			<umb-body-layout headline=${this.localize.term('user_selectUserGroup', false)}>
 				<uui-box>
 					${this._userGroups.map(
 						(item) => html`