Hi @Roman Rudziejewski,
For an image on a report server in native mode, type a relative path to the image in the Use this image box-for example, ../images/image1.jpg.
For an image on any Web site (including a report server in SharePoint integrated mode), type a full URL to the image in the Use this image box: for example, https://\<SharePointservername>/\<site>/Documents/images/image1.jpg
.
In addition, if you have set the Unattended Execution Account for the report server, please remember to re-start the report server.
Regards,
Zoe Hui
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