Option 1:
Via the Documents module > Select the type 'Person illness/injury document'
Click on the green + button > Select the related illness/injury > Upload the document > Add category > Save and close.
Option 2:
Click on the three dots at the end of the line of an injury/illness > Click on 'Edit'
On the 2nd tab of the illness/injury it's possible to upload 'Documents'
Option 3:
Click on the three dots at the end of the line of an injury/illness > Click on 'Historical view'
Click on the 2nd tab: 'Documents/Videos
General info: user functionalities depend on the roles & permissions settings. If a certain functionality does not work within your user account, this will be because you don't have sufficient permissions for this.