Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Maybe the following steps would be worth a try...
With your document open in Publisher...go to...Edit / Select All...then ...Edit / Copy.
Next...open Windows Paint and go to...Edit / Paste...then...File / Save As...
Choose a Save folder...
Enter a name...
Open the 'Save as type' drop window and choose JPEG...
Left click the Save button...