We have had various reports, both of success and failure, uploading new firmware that supports gcode to various Vigotec units.
I looked at http://vigotec.cn/software/VigoEngraverL7_v2.32-B20200814.zip which contains a file Standard_Grbl_v1.1f.hex which ought to enable using LaserWeb, Kiri:Moto, or Visicut. They ship avrdude.exe for windows (twice in that .zip file!), but it looks like it actually uses avrdude to do the upload, and I would expect that on Linux on your Raspberry Pi you should be able to use avrdude for Linux. However, I don’t know what avrdude command-line arguments would be required.
Also, I don’t see any offer from Vigotec to comply with the terms of the GPL for all the GPL software they are shipping. GRBL and Avrdude at least are GPL and they are legally required to ship the source code. I see nothing in that file, and nothing on their web site, offering source code. They are happy to declare their own copyright and state “All rights reserved” for their own web site, but apparently less interested in honoring the copyrights of others.
if they have a Window exe and it calls avrdude.exe you might be able to run a ‘strings’ on the EXE and glean the full call string with command options.
As for the GPL, I thought they were required to “provide” the source which if it is bog standard GPL and avrdude then they could/should just point to the source trees for those. Would have been better to provide the source snapshot with the other tools in the zip file but I don’t think that’s required. I’m often wrong so could be here too.