Can Apple please fix problems with ios 18 (mobile) and Safari on desktops

Considering Apple's Safari browser on both platforms you mention can access any number of websites out there, without any issues, I would think the source of the problem is specifically your website if its the only one having issues.

Apple cannot go into the billions of websites out there and make sure their browser works with specifically with them.

Its the job of the website creator to verify it works with all browsers including Apple's

If Apple had "bad code" then no websites would function. And yet, they do.

Unless you are doing something really weird on your website, it should work. If isn't I would verify your own code before blaming others.

I build websites for a living and I have never had any issues with Apple's Safari browsers on any platform.

So what exactly is the issue you are having? Perhaps if you explain what is wrong, someone can help you resolve it.

Run an HTML, CSS, and related compliance checkers on your websites, as a starting point.

Ensure the website meets HTML5, and isn’t using any vendor extensions except as strictly necessary.

Among the many validators available for this purpose:

https://validator.w3.org/

Various of the HTML authoring tools will also include validators and compliance tests. Some of the frameworks, not so much.

Something is wrong with that. Of course URL links work on Macs, iOS devices... everything. It's simply fundamental.

More information would help. You wrote "... no Apple users using ios 18 can use any of my websites" which suggests something amiss with that particular website code. We really can't help debugging website code, and Apple won't be able to help with that either. Perhaps consider participating in a WebKit developer forum.

Start here: WebKit | Apple Developer Documentation