XF 2.2 Help with Multi prefix

[Robert9]

          <xf:if is="is_addon_active('SV/MultiPrefix')">
              <xf:formrow label="{{ phrase('prefix') }}" rowtype="input">
                  <xf:macro template="public:sv_multiprefix_prefix_macros" name="select"
                            arg-type="resource"
                            arg-selected="{{ $resource.sv_prefix_ids }}"
                            arg-prefixes="{$resourcePrefixes}"
                            arg-name="prefix_id"
                            arg-href="{{ link('resources/prefixes', '', {'force_limit_prefix': 1}) }}"
                            arg-listenTo="< .js-prefixListenContainer | .js-categoryList" />
              </xf:formrow>
          <xf:else />
              <xf:formrow label="{{ phrase('prefix') }}" rowtype="input">
                  <xf:js src="xf/prefix_menu.js" min="1" />
                  <xf:macro template="public:prefix_macros" name="select"
                            arg-type="resource"
                            arg-prefixes="{$resourcePrefixes}"
                            arg-name="prefix_id"
                            arg-href="{{ link('resources/prefixes') }}"
                            arg-listenTo="#js-categoryList" />
              </xf:formrow>
          </xf:if>

I try to show the choosen prefixes in a form, but i fail here with trying:

arg-selected="{{ $resource.sv_prefix_ids }}"
arg-selected="{{ [$resource.sv_prefix_ids] }}"

What can i do to show them?