Run, enter the text you want repeatedly typed, enter the amount of time you want the text repeated (or sent) and enter the delay (can be 0).
Please use this software responsibly as some applications can terminate your account by spamming message (as per their individual ToS). No responsibility is held should your account be suspended, ratelimited or terminated.
Most applications, however will allow you to send several hundred messages by ratelimiting you (such as Discord, you can send upwards of 1000 messages, but it'll take a few minutes for them all to send).