Check Valve Timing (On timing chain)

[EMT with a Yaris]

Hoping anyone here can elaborate on the instructions within the service manual for Checking Valve Timing

My 2010 Toyota Yaris 4 door sedan has had a code on and off (Historic/Permanent) for about 14 month now regarding Retarted Cam Timing (P0012)

The Service Manual Instructions are as-follows (screenshot of page attached to this post aswell)
[Page ES-71][4 - Check Valve Timing (For loose and jumped teeth on timing chain)]

(a) Remove the cylinder head cover.
(b) Turn the crankshaft pulley, and align its groove with the
timing mark "0" on the timing chain cover.
(c) Check that the timing marks on the camshaft timing
sprocket and camshaft timing gear are facing upward as
shown in the illustration.
If not, turn the crankshaft 1 revolution (360°), then align
the marks as above.
OK:
Timing marks on camshaft timing gears are aligned
as shown in the illustration.
(d) Reinstall the cylinder head cover.

Im confused on how you would align the markings? I cant seem to find through the hunderds of pages this service manual instructions on how to adjust the timing chain.

Thanks for any and all of your help !