Problem with mqtt browser connection

I am writing my bachelor thesis and it is a web application but unfortunately I have this problem I am using flutter for the front end and I can’t connect to MQTT Broker I don’t know where the error is
I already used MQTT Client but unfortunately I found out that I have to use mqttbrowserclient and I don’t know what to do now
I tried but I couldn’t connect with the broker
Please I need help

Hello @mms ,

It is great to see your genuine interest in MQTT and HiveMQ. Please be welcome in our community.

Could you please share more details about your problem?

Thank you,
Dasha from HiveMQ team