Hi, just to mention, it might be worth taking a look at
(a) review some supported voip carriers / SIP providers you have access to in your 3cx instance
(b) cross check to see if any of them offer DID in your country? (ie, Malta)
(c) if yes - then you are fine, in theory.
there is no requirement that your SIP servers are in your geographic region. Clearly latency might be a bit lower if you can get a primary supplier who has servers in your location precisely. But strictly speaking it is not required. And many carriers/SIP trunk providers - have SIP Servers that are located ~all over the globe, so even if you use a provider in a ~not-so-close country, you can still pick a SIP server which is ~close enough that it will work ~perfectly fine.
case in point, I have a client I'm working with who has a 3cx self-hosted instance located in the UK. They recently wanted to light up on the 3cx, some extra DID located in Canada to support a local office near me / also in Canada. For this requirement, we are using a SIP trunk account with VoipMS - who are business based out of Montreal QC Canada I believe - the DID is for Halifax NS Canada - and then we've selected one of the VoipMS Servers 'close' to the 3cx server (London).
Client phone handset devices here in Halifax are linked to the 3cx Instance in UK. The SIP trunk provider is officially in Montreal. The POP for the SIP Trunk is in London. Despite feeling a bit helter-skelter, it all just works perfectly fine. No latency issues, no quality issues, it all just works.
so, I'm guessing with a bit of review and cross check, you can probably identify a supported SIP Trunk Provider / for your 3cx instance / who can give you a DID in your region / and ideally a SIP POP server not so far away / that it all works smoothly.
Tim