Hi there!
Thanks for your query.
Actually, there is no default way to do that.
You can change the alias which will change the last portion only. To do this, please go to SP Simple Portfolio items and change item alias. Then URL will be changed.
You can enable 'Remove IDs from URLs' from Global Options of SP Simple portfolio to get rid of numbers/digit ID from the last portion:
https://prnt.sc/1r811uh
https://prnt.sc/1r813hk
And the following blog may help you in general:
https://www.joomshaper.com/blog/making-joomla-site-seo-friendly-by-removing-id-from-urls
But these will not remove the item word from the URL. You can try SH404sef extension that may help you.
Best Regards