Pretty sure the A12 does not support Wireless charging , does support Fast Charging. From Manual :
Connect the USB cable to the USB power adaptor and plug the cable into the device’s
multipurpose jack to charge the battery. After fully charging, disconnect the charger from the
Launch the Settings app, tap Device care → Battery → Charging, and then activate the
feature you want.
• Fast charging: To use the fast charging feature, use a battery charger that supports
Adaptive fast charging.
• While charging, you cannot activate or deactivate this feature.
• You can charge the battery more quickly while the device or its screen is turned off.
Wireless charging not mentioned in Manual and this Samsung response says not compatible with A series https://www.samsung.com/us/support/Wireless Charging
Could also have a look at this review https://www.expertreviews.co.uk/mobile-phones/1413149/samsung-galaxy-a12-review
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 4.0,Android 12 Official Version.