Thank you both.
I have a section in his terrarium that is only tissue paper so my little one burrows there
Also, I contacted the biggest pet shop chain in my country to ask them if they could get Carefresh in their stores because I saw that they have it on their website for a country next to mine. They were kind enough to not only reply but say that they will of course put it in the stores here and contact me when they do so, it will just be the matter of time when they get it.
I’m calmer a little bit now, knowing that beech is probably okay and that some time in the future I will have something else to give him as substrate