URL Trouble – Can anyone Help?

HI all….

I have my site (https://www.reclaimedreflections.co.uk) uploaded to my FTP package that I rent from my host.
The FTP package is for another site https://www.barnardcastleglassandglazing.co.uk but I have been told that I can use the package to host multiple sites.
I have ‘mapped’ Reclaimed Reflections to the FTP package and all works well with my WordPress site (Construction ongoing) however, when you look at the url it reads through all pages —- https://barnardcastleglassandglazing.co.uk/reclaimedreflections/reclaimedglass/
I understand why and the path it follows but the host (123-Reg) have told me that the only way to change this is a setting in WordPress…..?
Is this correct ? Can anyone help me rectify this other than giving Reclaimed Reflections it’s own FTP package…?

Thank you in advance all….