If an ios application wants to be installed on a real machine, it must register and use Apple’s certificate and signature file. If it is used by batch users, it can only be released online through the App Store. As for internal testing of the company, or partners , if a small number of customers do simple testing, they can use third-party hosting platforms such as Dandelion, or they can provide the App's ipa package in the form of OTA through their own servers
There is only one formal channel, there is no choice. Others provide test hosting.
I recommend two, both are pretty good:
https://www.pgyer.com/
http://fir.im/
You can use a USD 299 account, and through enterprise-level publishing, you can realize the scan-and-download mode
UUIDMATCH
Enterprise accounts can publish internal apps
If an ios application wants to be installed on a real machine, it must register and use Apple’s certificate and signature file. If it is used by batch users, it can only be released online through the App Store. As for internal testing of the company, or partners , if a small number of customers do simple testing, they can use third-party hosting platforms such as Dandelion, or they can provide the App's ipa package in the form of OTA through their own servers