I need help, please

I’ve created a custom-context and after that create a misc destination for that custom.

But my problem now is, how to restrict this misc application to receive only one call per time?

What I do?:

Create a QUEUE;
Redirect calls from this QUEUE to misc application number;

But I don’t want to send two calls at the same time to this app. Only one person per time.

I need to control the number of lines redirected to this queue.

Might be better to state what you are trying to accomplish… and provide a little more info. Like Asterisk and FreePBX version.