Unable to send ephemeral (hidden) message

[tall knoll]

According to other answers the following code should send an ephemeral message:
await ctx.send('Message Sent ✅', ephemeral=True)
But when running the code, I get this error:

Ignoring exception in command message:
Traceback (most recent call last):
  File "/home/runner/bot/venv/lib/python3.8/site-packages/discord/commands/core.py", line 126, in wrapped
    ret = await coro(arg)
  File "/home/runner/bot/venv/lib/python3.8/site-packages/discord/commands/core.py", line 860, in _invoke
    await self.callback(ctx, **kwargs)
  File "main.py", line 39, in _slash
    await ctx.send('Message Sent :white_check_mark:', ephemeral=True)
TypeError: send() got an unexpected keyword argument 'ephemeral'  

This code seems to work for other people, so I'm not sure what I'm doing wrong.

Python Version: 3.8
Pycord Version: Development (installed directly from dev branch this morning)

[quick rapids]

ephemeral is only used on interaction responses.

[tall knoll]

That is what I'm trying to do, I realize I really should have made that clear in the original post. My bad.

[quick rapids]

Then why are you using ctx.send

That's now how you respond to interactions

[tall knoll]

oh. How am I supposed to respond to slash commands?

[quick rapids]

ctx.respond

b!rtfm pyc context.respond

[stray surge]

Best matches for context.respond in pyc

discord.ApplicationContext.respond
discord.ext.bridge.BridgeContext.respond