On your support website for this router firmware version is TL-MR3420(EU)_V5_211220

https://www.tp-link.com/en/support/download/tl-mr3420/v5/#Firmware

https://static.tp-link.com/upload/firmware/2022/202201/20220111/TL-MR3420(EU)_V5_211220.zip

Full version of this firmware 1.7.0 0.9.1 v0001.0 Build 211220 RC.36097n

But from auto update I got next version:
1.8.0 0.9.1 v0001.0 Build 211220 Rel.70276n

Why this version is no have on support website?

Where can I download this release?

I need it for offline update.
1.8.0 0.9.1 v0001.0 Build 211220 Rel.70276n