Generating sitemap without listing is fine

if I want all the listings to be in the sitemap so I can submit them to google the plugin page will go BLANK

If I check the sitemap on the web below are the error message and I have contacted my hosting to increase the memory limit so I don't know what is wrong that the bulk URL in the sitemap can be generated correctly

Check the attached and below web view error message

This page contains the following errors:
error on line 26452 at column 9: Extra content at the end of the document
Below is a rendering of the page up to the first error.

It looks like you have some unexpected character in file, maybe it was not stored properly.

What can you suggest that I should look for?

Because if I off the listing, everything will generate fine

This last code in sitemap file is always deleted by itself once the sitemap is not generate normal

</urlset>

Not right, that line is inserted as last line to file.
If there is problem before, this line will not get to file

So how do I locate the error?

If it is not in php logs, not too many ways.

PHP error back again after the hosting have set the memory to unlimited

PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 20480 bytes) in /home/site/public_html/oc-includes/osclass/model/Item.php on line 1352


 foreach($extraFields as $key => $value) {
        $item[$key] = $value;
      }

      $results[] = $item;
    }
    return $results;
  }
}

/* file end: ./oc-includes/osclass/model/Item.php */

How do I solve this

It means number of items you wants to out into file is larger than your hosting memory.
Can be fixed by increasing php memory, but also just until it is reached.
Alternative is to reduce items in sitemap.

If I set the php memory to 512M or 1024M instead of the unlimited memory the sitemap will generate with 40,000 URL, I will took so long like 35.47 seconds.

So it will return an Error on the google search console because google could not wait for that  amount of time to load sitemap

So how can I make the generating fast the execution time as also been increase but still taking more time to generate sitemap

Generation of sitemap has nothing common with google itself, as dile is sent to google on e it is generated.
Your only problem is you wants too much into 1 file with limited resources.
Solution was already provided - reduce amount of urls or increase memory.
No better solution will & can come.

How do I split the sitemap like sitemap1.xml
sitemap2.xml

@oneloveb
File size is not problem.
It is not simple to do something like distributed sitemap that would consists of 10 files or so.

Let assume that I have reached the google sitemap limit of 50k
now I need to submit another 50k sitemap to google

Is it not possible to do in Oslcass?

@oneloveb
Everything is possible until you have enough time or money.