IOS bluetooth integration

Hi, I am having an issue in bluetooth integration in ios. We need to connect ios bluetooth with Raspberry pi 3 where we are using rfcomm for sending text messages. Can anyone please help me how we can do it in ios? I can send message in android but not in ios?
I am trying to do the exact same thing but with the Raspberry pi 4. I have got two iPhones to send text to each other using one of Apple's Swift examples but everything I try with Python in Windows doesn't work so I haven't tried the Raspberry either and have come to the conclusion that rfcomm might be the way but I can't find any examples. I am finding the bluetooth communication far more difficult than it should be.
IOS bluetooth integration
 
 
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