to Send Through Web API, you have to pass the following arguments:
token The Oauth2 Token you will get from slack when configuring your bot or app, Or you can use Legacy tokens instead
channel The place you want to send the message, Channel ID if it is a channel, or User ID if it is a User.
text As the name say, the message you want to send
as_user Whether you want to send the message as your name or as a Custom name, This a boolean method, Means its Only True or FalseNote: To configure a custom name its in another argument we will reach.
attachments A JSON-based array of structured attachments, presented as a URL-encoded string.
username The name you want to appear as the sender of the message, only works if as_user is false, if as_user is true, it will ignore this argument.
Hope this help.
and please next time share a code so we can help, here there is not just 'I need...'
its a place where you share code and then ask 'I need...' so we can help