Shower facilities or Refresher Room

My friends and I will arrive via bus and drop at Abeno Harukasu (JR Tennoji Station). Since we arrived early at around 7 AM, would like to know if there are any shower facilities nearby or a refresher room?

There are public bath houses nearby. Wako and Hinodeyu open from 06:00, depending on the day.

If you use an Internet cafe, you can also use a shower.
This store has a free shower and a coin laundry.
https://www.kaikatsu.jp/shop/detail/20720.html
This store charges for a shower.
https://www.kaikatsu.jp/shop/detail/20946.html

Business hours are until 8:45, but you can also use Spa World.
You cannot use the bedrock bath.
https://www.spaworld.co.jp/english/
It is a 15-minute walk from Osaka-Abenobashi station.

Note that long distance buses are not major tranportation means in Japan. Yes there are some, but most of the tourists in Japan use train system (such as Shinkansen). Abeno Harukasu bus stop is just a bus stop. Not a terminal or a building.

https://www.bushikaku.net/article/70020/images/40024/

Even the largest bus terminal in Japan (Busta Shinjuku) does not have shower rooms within it.