Hello,
It is always better and Efficient to charge your Mac with the USB-C/Thunderbolt 3 port on the Mac directly using the supplied original charger. But if you want to charge it with a dongle make sure to be using the USB-C port on the Apple USB-C Digital AV Multiport adapter as this is designed for power delivery through that port to the Mac . But, if you are using any third party dongles/adapters do avoid it as 3rd part dongles/adapters for charging can damage you Mac.
I tried using the AmazonBasics digital AV multipart adapter ( which costed less that half of the price of apple one) and it forked fine for a week and then my Mac stopped charging. Then after a few minutes the computer got hot and turned off. Then I took it to the Apple Authorised Service centre and got it checked. They said that the motherboard was fried up due to using a bad third party ( non-apple ) accessory. I had to get it repaired by paying for it ( payed almost 1300 USD ) for getting it repaired. I wa like my heart was broken.
So, don't use any kind of third party accessory especially for charging the Mac .
Hope this helps you.
Thanks you.