There are options for making outside spaces more protected such as a meshed catio (we used safecat and woodenart as they build bespoke to fit what you need), purrfect fence (we bought from here) and protectapet. 

https://safecatuk.com – Safecatuk

https://www.woodenart.org.uk/

https://purrfectfence.co.uk

https://protectapet.com

https://www.wirefence.co.uk/catio-ideas/

Training to use a harness

https://supakit.co/blogs/cat-guides/how-to-harness-train-your-cat?

We also have internal work done (removable pet mesh doors etc) by Harlequin Designs to make our indoor space safer to try to accommodate Abys!  I recommend an internal screen door or security porch.

https://www.facebook.com/profile.php?id=100070167273447

Here are some suppliers of mesh screens for windows and doors etc, varying in design and price

https://www.streme.co.uk/shop/pet-screens?

https://newblinds.co.uk/roller-insect-screens-roller-pet-screen-window?

https://www.premier-env.co.uk/magnetic-fly-screens/

https://www.amazon.co.uk/Legend-Window-Screen-Scratch-Resistant/dp/B08BZ1DKFF

https://www.amazon.co.uk/GAUDER-Type-B-Magnetic-Tape/dp/B07FFBWLQV/ref=sr_1_3_sspa?crid=3UZQZTKPUF1Y5&keywords=magnetic+strips+for+blinds&qid=1707139665&sprefix=Magnetic+strips%2Caps%2C302&sr=8-3-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

https://www.flatcats.co.uk/window-protection-what-are-flat-cats.php

https://www.amazon.co.uk/SHRRL-Reinforced-Screen-Prevent-Running/dp/B09QCL1BB8/ref=sr_1_51?adgrpid=147362436645&hvadid=658122563404&hvdev=t&hvlocphy=9045605&hvnetw=g&hvqmt=e&hvrand=1984352441178118977&hvtargid=kwd-504403242642&hydadcr=20939_2250200&keywords=pet+mesh+window+screen&qid=1707141031&sr=8-51

https://www.amazon.co.uk/MOTT-50-Self-Adhesive-Protection-Anti-escape/dp/B0B7714T66/ref=sr_1_7?adgrpid=147362436645&hvadid=658122563404&hvdev=t&hvlocphy=9045605&hvnetw=g&hvqmt=e&hvrand=1984352441178118977&hvtargid=kwd-504403242642&hydadcr=20939_2250200&keywords=pet+mesh+window+screen&qid=1707140747&sr=8-7

Information on plants both safe and poisonous to cats

https://www.aspca.org/pet-care/animal-poison-control/cats-plant-list

We have experience to share!