Hey y’all, I have ordered the parts to build the Zidex and unfortunately the IZTOSS 2028 Black Corner Angle L Brackets are not available online.
Can y’all please help me find an alternative for these?
I found this link.
Thanks @Xanvier. I reached out to @Dr.D-Flo and he suggested this as a replacement https://www.amazon.com/uxcell-Outside-Joining-Bracket-Aluminum/dp/B07TJQMYY1/ref=sr_1_2?dchild=1&keywords=90+Degree+L+Shape+Outside+Joining+Plate&qid=1600284663&sr=8-2 which looks different than what you suggested and I am not sure which one to pick now 
It depends on where you need to use them as they mount to the side as opposed to the corner. In reality if the new ones he posted wont interfere whith anything when mounted the should alow more stiffness as they use up to 5 fasteners instead of 2.