I selected the photoshop and Lightroom free trial for 19.99. I was able to download Lightroom but how to add photoshop?

What operating system and version number?

Have you installed Photoshop from your Creative Cloud Desktop App?

And does your system meet the required specs and have enough empty hard drive space?

https://helpx.adobe.com/photoshop/desktop/get-started/technical-requirements-installation/adobe-photoshop-on-desktop-technical-requirements.html

does your computer meet specs for ps, https://helpx.adobe.com/creative-cloud/system-requirements.html

You don’t see Photoshop in the Creative Cloud desktop app?