I searched for “lightroom for ipad to photoshop for ipad” at adobe.com. One pass and I think this will answer your needs. YMMV, meaning take Ai help with a box of salt.
The results of my search:
https://www.adobe.com/home/search?query=lightroom%20for%20ipad%20to%20photoshop%20for%20ipad
“Round-trip Editing Between Lightroom and Photoshop on iPad
To seamlessly edit photos from Adobe Lightroom on your iPad in Adobe Photoshop on the iPad, follow these steps:
- Open your photo in the Detail view in Lightroom on your iPad.
- Tap the export icon in the upper-right corner.
- Select Edit in Photoshop from the export menu. Your photo will open in Photoshop on the iPad with all Photoshop tools available.
- Make your desired edits in Photoshop, including adding layers or advanced retouching.
- When finished, tap Send to Lightroom in the upper-left corner to return the edited photo back to Lightroom. The edited photo appears alongside the original in your Lightroom library, marked with a Photoshop icon if it contains layers.
Additional tips:
- You can create a Photoshop cloud document from Lightroom by tapping the three dots in the Lightroom to Photoshop workspace and selecting Create Photoshop cloud document. Note that once saved as a cloud document, the photo cannot be sent back to Lightroom.
- If Lightroom adjustments flatten your image layers, you can reset adjustments in Lightroom to recover layers when round-tripping back to Photoshop.
This round-trip workflow leverages the strengths of both apps for powerful mobile photo editing on your iPad. Try it to enhance your creative projects with ease.”