How to get access key?
How to get access key for legacy designation?
How to get access key for legacy designation?
There are details within the 'Related Article' link above, which suggest
information that may help. Other Apple articles might be found online.
"A Legacy Contact is someone you choose to have access to the data in
your Apple account after your death. Learn about the information that’s
shared with your Legacy Contact and how to add one or more Legacy
Contacts."
• How to add a Legacy Contact for your Apple ID - Apple Support
//support.apple.com/en-us/HT212360
Seems this article has significant detail to figure how to begin doing so.
A person should be able to notify their intended Contact as mentioned.
"The access key is extremely important—your Legacy Contact must have
both the access key and your death certificate to request access after
you pass away. Then they'll need the access key again to set up a legacy
contact Apple ID and access your data."

If you add someone who doesn’t have an Apple device
or can't access Legacy Contact settings on their device,
you'll need to give them a physical copy of the access key.
You can print a copy of the access key and give it to them,
send them a PDF or screenshot of the page, or save a copy
with your estate planning documents.
Learn how your Legacy Contact can request access to your Apple account.
Learn what to do if a Legacy Contact you recently added is unexpectedly removed.
There are details within the 'Related Article' link above, which suggest
information that may help. Other Apple articles might be found online.
"A Legacy Contact is someone you choose to have access to the data in
your Apple account after your death. Learn about the information that’s
shared with your Legacy Contact and how to add one or more Legacy
Contacts."
• How to add a Legacy Contact for your Apple ID - Apple Support
//support.apple.com/en-us/HT212360
Seems this article has significant detail to figure how to begin doing so.
A person should be able to notify their intended Contact as mentioned.
"The access key is extremely important—your Legacy Contact must have
both the access key and your death certificate to request access after
you pass away. Then they'll need the access key again to set up a legacy
contact Apple ID and access your data."

If you add someone who doesn’t have an Apple device
or can't access Legacy Contact settings on their device,
you'll need to give them a physical copy of the access key.
You can print a copy of the access key and give it to them,
send them a PDF or screenshot of the page, or save a copy
with your estate planning documents.
Learn how your Legacy Contact can request access to your Apple account.
Learn what to do if a Legacy Contact you recently added is unexpectedly removed.
How to get access key?