If Share My Location is not working on iPhone, you won’t be able to share your Location with anyone using iMessages, Apple Maps, WhatsApp and other Apps that support this feature.
In general, the most common reason for Share My Location not working on iPhone ends up being due to the Location Services feature not being enabled on iPhone.
Apart from this, the issue of Share My Location not working on iPhone could be due to the User being signed-out or not being loged-in to iCloud and other reasons.
Share My Location Not Working or Greyed Out on iPhone
If “Share My Location” is not working on iPhone or the Share My Location setting is grayed out, you should be able to fix the problem using the following methods.
1. Sign-in to iPhone
The Share My Location option becomes available on iPhone, only if you are signed-in to your device.
1. Open Settings > tap on Sign in to your iPhone option.

2. Sign-in to your device by entering your Apple ID and Password.
3. After you are Signed-in, tap on Find My.

4. On the next screen, you can enable Share My Location option by moving the slider to ON position.

Note: Make sure the message below Share My Location says “Share your Location with family and friends…”.
2. Enable Location Services
As mentioned above, the most common reason for “Share My Location” feature not working on iPhone is due to the Location Services being disabled or not being enabled on iPhone.
1. Go to Settings > Privacy & Security > Location Services.
2. On Location Services screen, make sure the toggle next to Location Services is turned ON.

3. After this, tap on Share My Location (it should now become available).

4. On the next screen, move the toggle next to Share My Location to ON position and read the Message below this entry.

Note: Share My Location feature is working on your device, if you see the message reading “Share your Location with family and friends in Messages…”.
3. Disable Restrictions
If Share My Location feature is greyed out on your iPhone, the problem is due to Location Services feature being locked or restricted on your device.
1. Go to Settings > Screen Time > Content Privacy & Restrictions.

2. If prompted, enter your 4-digit Screen Time Password > On the next screen, tap on Location Services.

3. On Location services screen, select Allow Changes option, scroll down and tap on Share My Location option.

4. On the next screen, move the toggle next to Share My Location to ON position.

Hope one of the above methods has helped you fix the problem of Share My Location not working or Share My Location setting being Locked or Grayed out on your iPhone.