used the recipe from British sourdough on tiktok but added hundred grams of inclusions in 2nd stretch and fold https://vm.tiktok.com/ZNRKtuf1S/

followed the recipe exactly and used the aliquot method too judge the bulk fermentation as my thermometer has run out of charge. I dont own a Dutch oven and my oven is a microwave oven which causes some problems, I cannot fit water as well to create steam and I don't know how regulated the temperature is. think I am quite happy with the texture of the bread but it never seems to rise upwards it only spreads outwards, the bread is not dense it just doesn't seem to have the oven spring and upward rise that I desire. I am not sure if my starter is weak, I have had it for more than a year but I keep it in the fridge for long periods of time which might have weakened it but before baking it always doubles. I am not sure if it is under or over proofed, I did use the aliquot method and dough looked well fermented but i only cold proofed for 4hrs as I don't think my fridge was cold enough as it kept growing in the fridge. I am also wondering if I am not shaping it correctly and not creating enough tension.

any help would be greatly appreciated thanks 

bread not getting oven spring