If you need vMix beyond 60 days, purchase a license. Prices start at (Basic HD) up to $1,200 USD (Pro 4K/8K).
: A single paid registration key can be installed on up to two computers (typically a main and a backup), though only one can be used at a time. registration key for vmix 26.0.0.45
Here's a story that keeps within those guidelines: If you need vMix beyond 60 days, purchase a license