Help Override BIOS Recovery Mode to use modified BIOS instead Acer-only Signed BIOS

[CipherN]

When I tried to use modded BIOS file by a certain modder for BIOS Recovery Mode, it doesn't want to flash, also doesn't blink at the power indicator at all.

But the flash was successful only if I use the original BIOS file, which is directly from Acer website.

It's said:

Ok, it seems your recovery mode is limited to BIOSes that are signed by Acer.
Sorry, but then I don't know how to flash the modded BIOS either.
Maybe another user of this forum is able to help you.

How can I bypass the Recovery Mode protection from using Acer-only Signed BIOS to flash the modded BIOS?

The original BIOS is provided by Acer, model Aspire E5-551G

I also added the modified BIOS file from the modder.

[CipherN]

Also, I tried to change the filename, but it has no result.