Permalink Manager allows to set the custom URIs when the posts, pages, custom post type items or products are imported with WP All Import plugin.
To properly import the permalinks, please open “Permalink Manager” metabox and copy the content column tag with custom URIs.
Please also keep in mind, that the custom URIs in import file (XML, CSV, TXT) should contain only the URI, not the full URL:
What would happen if I leave the Permalink Manager section empty?
If you leave the field empty, Permalink Manager will use the default custom permalinks (based on Permastructure settings) for all imported elements.