Workspace owners and admins can decide who can set posting permissions for the #general channel:

1. From your desktop, click on your workspace name at the top left.
   
2. Select Settings & administration from the menu, then click on Workspace settings
3. Click the Permissions tab at the top of the page.
4. Scroll down to Channel management and click Expand.
5. Below People who can manage posting permissions in channels, select an option. 
6. Click on Save.

Workspace owners and admins can decide who can set posting permissions for any channel:

1. From your desktop, click on your workspace name at the top left.
   
2. Select Settings & administration from the menu, then click on Workspace settings
3. Click the Permissions tab at the top of the page.
4. Scroll down to Channel management and click Expand.
5. Below People who can manage posting permissions in channels, select an option. 
6. Click on Save.

Org level

Org owners can set an organisation policy to specify who can manage posting permissions:

1. From your desktop, click on your workspace name at the top left.
   
2. Select Settings & administration from the menu, then click Organisation settings.
3. Click  Settings in the left column, then select Organisation policies.
4. Select the Permissions tab.
5. Next to Channel management restrictions, click Add policy. 
6. Under Who can manage posting permissions in channels, select an option from the drop-down menu.
7. Click Save policy, then Confirm policy.

Workspace level

Workspace owners and admins can decide who can set posting permissions for their workspace:

1. From your desktop, click on your workspace name at the top left.
   
2. Select Settings & administration from the menu, then click on Workspace settings.
3. Click the Permissions tab at the top of the page.
4. Scroll down to Channel management and click Expand.
5. Choose who can manage channel posting permissions.
6. Click on Save. 

Tip: In default org-wide channels, posting is restricted to owners and admins only.