I did create a how-to some month ago:
A lot of vendor files you can find here:
https://github.com/TheMuppets/
https://gitlab.com/the-muppets
The twolip vendor files seems to be there.
A good source is also XDA:
https://xdaforums.com/f/xiaomi-redmi-note-6-pro-roms-kernels-recoveries.8410/
If you don’t find vendor files you can also try to extract for LineageOS ROMS:
https://wiki.lineageos.org/extracting_blobs_from_zips