Still not able to load uxp plugin in 25.2.3

No Plugin menu in Premiere pro. No connected Host in UDT.

Is it still only available in Beta version?

Yup. Still in Beta.
-Dan

Is there a date, when it’ll be available in not beta-Premiere

No official date; the plan is to officially release UXP extensibility in PPro, this calendar year.

Any update? It’s 2026 now.

Yes! Premiere Pro 25.4 (non-beta) officially supports UXP plugins.