Just discovered it takes 2 particular steps to change the WordPress settings on Namecheap’s web hosting, and it took me a while to find the answer. Hopefully this blog post will make it easier for you to find the answer here. By default, Namecheap allows for a maximum upload file size of 32MB.
Step #1 = create and edit a custom php.ini for your WordPress self-install
And in that php.ini, either modify or add these lines (for 64MB max file upload size):
Step #2 = update the .htaccess file to use that custom php.ini you just updated
But, depending on your cPanel configuration (maybe?), you may not be able to view/edit a .htaccess file in the cPanel File Manager. I had to view/edit my .htaccess file via FTP. (cf. Web Hosting Tutorial: Uploading files for your website using FTP)