This plant looks like someone put it in the container and then forgot about it. A bit of TLC is recommended.
First, thin out the plant by removing some of the older branches and the especially thin and scraggly ones down to soil level. This will encourage new growth which then will bear flowers next year. For the first time, I would probably be a bit “brutal” and take out a quarter or up to a third of them this year. You can recognize the older branches by the thicker, darker bark and probably more lichen on them, but it’s not important now (just observe the difference when you get new growth and prune again the following years). The goal is to repeat the exercise annually until you have effectively removed all old branches over four to five years, roughly.
If you feel the shrubs is too tall, you can also shorten some of the branches, but don’t take all tips now, or you may take too much leaf mass - the plant needs to do photosynthesis.
Another point is that the shrub is sitting in a container, which means reduced root space and possibly nutrient depletion, if the previous owner was as diligent with fertilizing as with pruning. Find a good shrub fertilizer (ideally something slow-releasing that you use once or twice a year) and use it according to the package directions.