Since you have Magisk you can install busybox as a module.
If you do not want to manually locate and download the zips from XDA (osm0sis), install Fox’s Magisk Module Manager. Think of it as an app store for Magisk modules.
I finally found the FoxMagiskModuleManager and you seem to be having trouble keeping it.
However, their README quickly directs me to a PWA where there is a Magisk Modules Repository by Androidacy.
I found the download from there very handy, it has the sha256sum handy and a VirusTotal check.
Are you saying that you have problems using Fox’s MMM? I do not understand.
Androidacy is one of two repos included in the app. I personally do not care to deal with Androidacy directly. An ad-ridden, captcha-driven, sometimes frustrating place.
Basically… I think I won’t need to incorporate too many modules, just some specific needs. That is precisely why from the PWA it was enough for me to get each official download link.
I also checked out the Magisk Modules Alt Repo, both of which are just a git clone away, lovely.
I repeat, I’m not going to incorporate too many modules, and… simply so as not to install another apk. Otherwise, when I find myself testing modules more frequently, I wouldn’t hesitate to install it.