For customers, Global ID default to 0088 (allowing GLN, DUNS, etc. to be used). This matches quite well with the optional record "GLN".

Conversely, no Global ID is being set for YOURCOMPANY, so that the GLN cannot be used to link the seller and buyer to one another. One may also opt for 0088 as its default value. However, not all Fakturama users may be anticipated to have a GLN and a GS1 subscription. It might be interesting therefore to let the Fakturama administrator choose its own Global ID. For example, by selecting 0009 (the SIRET register), a company registered in FR would allow combining the yet-to-be-created field YOURCOMPANY.GLOBALID with the company's SIRET number as follows:
0009:SIRET (where SIRET is a 13-digit number), which uniquely identifies the company at the EU level.

Now, a sample global ID for a German company: '9930:DE812871$$$' (9930:MwSt)

See here the full EAS code list:

https://ec.europa.eu/digital-building-blocks/sites/spaces/DIGITAL/pages/467108974/Registry+of+supporting+artefacts+to+implement+EN16931#RegistryofsupportingartefactstoimplementEN16931-Codelists