PBO2 is a feature set of the processor and BIOS that operates independently of any software. (ie. you don't have to install Ryzen Master to use those features) Ryzen Master is an application you can use to monitor and/or tweak various PBO settings.
List your full system specs as there are a few reasons why Ryzen Master would not install. If for example, you don't have a Ryzen processor, if your system is an OEM built, if you're not using the correct version, etc.
Ryzen R7 5700X | B550 Gaming X | 2x16GB G.Skill 3600 | Radeon RX 7900XT
Ryzen R7 5700G | B550 Gaming X | 2x8GB G.Skill 4000 | Radeon Vega 8 IGP
Ryzen R5 5600 | B550 Gaming Edge | 4x8GB G.Skill 3600 | Radeon RX 6800XT