[Plugin: My Custom Widgets] How to use php in the code…

I just downloaded ‘my custom widgets’. It seems to be working great except when I have some php in my code. I have been looking for an example of how to add the php. I fell over this by copying some already working code that I had handcoded into my sidebar. It had one line of php in it, surrounded by html like:

html…
<?php a line of php code ?>
html…

It was rejected and didn’t work.

Can someone help me figure out how to use this feature?

Thanks.

https://www.ads-software.com/extend/plugins/mycustomwidget/