Problème impression

If you give details of your printer model and your workflow in Lr-Classic, there might be someone with a similar system to give an answer. If you search Googly for an answer there are many suggestions. Post as a new question.

Start by checking every option in your printer set up dialog- Paper size, etc. (Hint: Do not use the default Lightroom Templates- they are all for 'Letter' size paper. )

I note your photo Cell size is  A4 cm dimensions- Have you set printer to "Borderless"?

", l'aperçu est vide "   the preview is empty.  Yes that is to be expected and it never does show the photo in the small preview panel. That is normal and how it always works. The 'preview' is a preview of the template only, not the photo.

Choose a multi image template and you will see a preview of the cells on the page.

"c'est une page blanche qui sort." "a blank page that comes out"- That is another problem that needs more investigation- perhaps something in the Printer Setup dialog.  The templates supplied by Adobe are never suited to your own printer.  You design the print page and save as a user template for your printer.