Alternative solution for pank-aid backorders
Enzyme Diane
Enzymes distributor for the treatment of EPI for dogs and cats. Really affordable prices : https://enzymediane.com/
Pan-Tenex
Enzymes distributor for the treatment of EPI for dogs. Concentration 10x and very affordable price: 
https://www.pantenexdogenzymes.com/product/pan-tenex-canada
Wonder Laboratories
Distributor for Vitamin B12, With intrinsic to fill the cobalamin (B12) deficiency of your EPI dogs : https://www.wonderlabs.com/itemleft.php?itemnum=K9688
EPI4DOGS
Epi4Dogs Is a not-for-profit public charity. Recommendations on this site are supported by EPI veterinary protocols, EPI veterinary researchers, veterinary publications, as well as the daily observations and experiences of EPI animal owners. Epi4Dogs is GDPR compliant. https://epi4dogs.com
For more details on the EPI, you can consult this.