send-icon slot dont work

<ChatWindow>
<template #send-icon>
   <svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
         ......
  </svg>
</template>
</ChatWindow>



it works:

<template #room-header="{ room, userStatus }">
  {{ room.roomName }} - {{ userStatus }}
</template>

what could be wrong?