generally, you dont want to stress the PSU over 80% or it will have a higher chance to blow up within a couple years, and its the most energy efficient at 80% load.
so with for example 500W PSU, you actually want to be around 400W load. thats around 225 for the RTX2060, 100-150 for CPU depending on whether you overclock it or not, and then you already have only 25-75 left for all the other components.
also, the total W spec for PSU often includes the 5V rail, the maximum power on the 12V rails for this "450W" be quiet PSU is only 420W. and it has 2 12V rails, which then have 210W each. 80% of 210 is 168W per rail, in total that is 336W, which is just BARELY enough to run a pc with 95W cpu and 225W gpu. i definitely wouldnt recommend it. this PSU cannot run the GPU on a single rail. you cant overclock CPU with it.
thats why i would recommend at least 600W for a single heavy gpu setup like this.
i have Corsair AX850 PSU myself from 2010 when AMD cpus were very power hungry and also had 2 225W GPUs and everything overclocked. it drew up to 775W from the wall socket in stress test benchmarks. its warranty expired in 2018. never had to worry about it. it did cost 150 euro.