even after I added <fill>..... I still don't know how to apply it to cell:
<c t="inlineStr" fillId="3" ><is><t>{{val}}</t></is></c>
is not the way to go :(

Thank You I will Check this ^_^

it's an empty template I downloaded it from Google Drive, just created an empty google sheet downloaded it then uploaded it as a template, please check this link that I forked from the playground https://playground.jsreport.net/w/anon/nDSs3WAd

Xlsx Recipe: add image fail when using a template
It works on empty example but if I upload a template I get an error :

Error while executing templating engine. Cannot read property 'r:id' of undefined. Error on line 270:98.

  268 |     var drawingFullName
  269 |     if (this.ctx.root.$xlsxTemplate['xl/worksheets/' + sheetFullName].worksheet.drawing) {
> 270 |       var rid = this.ctx.root.$xlsxTemplate['xl/worksheets/' + sheetFullName].worksheet.drawing.$['r:id']
      |                                                                                                  ^
  271 |       this.ctx.root.$xlsxTemplate['xl/worksheets/_rels/' + sheetFullName + '.rels'].Relationships.Relationship.forEach(function (r) {
  272 |         if (r.$.Id === rid) {
  273 |           drawingFullName = r.$.Target.replace('../drawings/', '')


logs:
+0      Starting rendering request 987 (user: null)
+3      Rendering template { name: excel-image, recipe: xlsx, engine: handlebars, preview: true }
+4      Inline data specified.
+5      Resources not defined for this template.
+11     Base url not specified, skipping its injection.
+11     Rendering engine handlebars
TypeError: Cannot read property 'r:id' of undefined