forgejo/templates/repo/issue/view_content/reference_issue_dialog.tmpl

<div class="ui small modal" id="reference-issue-modal">
	<div class="header">
		{{.locale.Tr "repo.issues.context.reference_issue"}}
	</div>
	<div class="content" style="text-align:left">
		<form class="ui form" action="{{printf "%s/issues/new" .Repository.Link}}" method="post">
			{{.CsrfTokenHtml}}
			<div class="ui segment content">
				<div class="field">
					<span class="text"><strong>{{.locale.Tr "repository"}}</strong></span>
					<div class="ui search normal selection dropdown issue_reference_repository_search">
						<div class="default text">{{.Repository.FullName}}</div>
						<div class="menu"></div>
					</div>
				</div>
				<div class="field">
					<span class="text"><strong>{{.locale.Tr "repo.milestones.title"}}</strong></span>
					<input name="title" value="" autofocus required maxlength="255" autocomplete="off">
				</div>
				<div class="field">
					<span class="text"><strong>{{.locale.Tr "repo.issues.reference_issue.body"}}</strong></span>
					<textarea name="content" class="form-control"></textarea>
				</div>
				<div class="text right">
					<button class="ui green button">{{.locale.Tr "repo.issues.create"}}</button>
				</div>
			</div>
		</form>
	</div>
</div>