Adding help text to SOLR search block

Hello, Apache SOLR 7.x-1.8 is functioning properly. However, I have received a request from the client to add help text above the facets (as seen in image). Typically I would modify block.tpl.php by creating block--block--[delta].tpl.php. However, when I scroll through /admin/structure/block hovering over 'configure', I find edit-blocks-facetapi-gsiy4fr9gu0zss0bfms1y9qiipidf1wu-configure.

Is there a way to pass this content through a custom block template? If not, what is a better approach to insert a text string?