These instructions assume that you’re signed in to your device with your Apple ID and Keynote is set up to use iCloud Drive.
Do one of the following:
If the presentation is open: Tap
. If you can’t see the button, tap Edit [icon] at the top of the screen, then tap 
.If the presentation is closed: In the presentation manager or Files app, open the Keynote folder in iCloud Drive, tap Select in the top-right corner, tap the presentation (a tick appears), tap Share at the bottom of the screen, then tap Add People.
Tap Share Options.
Below Who Can Access, tap an option:
People you invite: Only people you invite who sign in with an Apple ID can open the presentation. People don’t need to have an Apple ID before you invite them; however, they need to create one before they can open your shared presentation.
Anyone with the link: Anyone who has the link to the shared presentation can tap or click the link to open the presentation. To protect it with a password, tap Add Password.
If this presentation already has a password, it applies to the shared presentation as well, so you don’t need to enter a new one. If you want to change it, tap Change Password.
Below Permission, tap an option to set what others can do:
Can make changes: People can edit and print the shared presentation.
View only: People can view and print the shared presentation but not edit it.
If you set access to “People you invite” (in step 3), you can change individual permission settings after you share the presentation.
If you have iOS 15 or iPadOS 15 or later installed and you don’t want all participants to be able to invite others, turn off “Anyone can add more people.”
Tap Add People in the top-left corner.
Tap a method for sending the link.
To send the link using a service like Twitter, that account must be set up on your device. (If you already use that account on your device, then it’s set up; if not, set it up in Settings.) To use a service that’s not listed, tap Copy Link.
Type an email address or phone number for each person.
If you invite someone using an email address or phone number that isn’t associated with their Apple ID, they won’t be able to accept the invitation until they add the email address or phone number to their Apple ID. Instructions are provided when they tap or click the link in the invitation.
Enter any other requested information, then send or post the message.
If you chose Copy Link, tap where you want to paste the link, then tap Paste.
The link appears in the body of the email, message or post along with the presentation title — make sure you don’t edit or delete it.
Important: When you tap Share, a link to the presentation (which includes its title) is created on iCloud. If the title or content of the presentation is confidential, make sure you ask recipients not to forward the link to anyone else.
After you share a presentation, a tick appears on the Collaborate button 
to indicate the presentation is shared. To see all your shared presentations, tap Recents at the bottom of the presentation manager.