If you know how to read such an article, you will find all the answers you are looking for.
I don't support this government so don't ask me to explain their deeds. They are playing some stupid balancing between EU and Russia which makes no sense to me.
If you are honestly interested in, this is pretty much a good read, except a thing or two, but overall OK:
https://rs.boell.org/en/2022/03/25/serbias-position-context-war-ukraine-reasons-and-perspectives
Regarding the weapons export to Ukraine, yes they do so, mostly basic stuff since this is what is produced in Serbia. But - due to fear of Putin repercussions - and you will not protect Serbia in case of troubles - most are done in undercover operations or via middlemen. All of the depots with much sought after Eastern 152mm shells are emptied and sent to Ukraine through third countries, most often Bulgaria.
Last summer a big Ukrainian cargo military plane, loaded with Serbian weapons, crushed in Greece. It was officially heading to Bangladesh but it's a public secret it was going to Ukraine via strange routes. Go figure....
https://www.dw.com/en/mystery-plane-crash-were-serbian-weapons-headed-for-ukraine/a-62574069
"There is also speculation as to whether the weapons were not actually destined for Bangladesh at all but for Ukraine. Both Defense Minister Stefanovic and the manager of the Ukrainian company Meridian, which owned the downed plane, have denied this.
Expert believes that important questions remain. "The public is owed an answer as to why a Ukrainian plane was transporting Serbian weapons right now, while a major international conflict is raging on Ukrainian territory," he said.
The political scientist sees the affair as an expression of
Belgrade's "seesaw" policies , attempting to balance between different major international powers.
"This would mean, on the one hand, secret munitions for Ukraine in order to please the West," he said. "On the other hand, concessions are being made to Russia by Serbia. All of this is part of the behavior of Belgrade's elites, their balancing between different international powerhouses in order to buy themselves services in return. For Serbia, the question is now whether these policies will collapse at a certain point because one of those powerhouses is angry."
They also allowed military convoys aimed to Ukraine transit via Serbia, something that Orban didn't.
https://www.euractiv.com/section/po...-to-ukraine-should-not-hurt-russia-relations/