Deciding which EVSE to buy will feel like Alice going down the rabbit hole. Start first by figuring out the max kW or Amps your LEAF can accept. Perhaps the easiest is to go to a public station that shows the kW while charging.
Then price Vs quality:
Cheapest: generic chinese like the link Alozzy gave. Usually OK, but I do not gamble where electrical safety is concerned.
Next cheapest: the generic brand of clipper creek called AmazingE (derated but good quality) -- https://www.amazon.com/AmazingE-Charging-Station-Electric-Equipment/dp/B06XSLYDLH/ref=sr_1_20?keywords=amazing-e+evse&qid=1639135630&sr=8-20
American: Clipper creek, JuiceBox, EnelX, Grizzl-E, ChargePoint
IIRC, there is a 30% federal tax deduction available for 2021
My advice: Choose between the AmazingE (3.8 kW, 14-30 plug, $350) and the Grizzl-E (9.6 kW, 14-50 plug, $460 for 18 ft cable).
You are probably going to find that the extra costs/hassles involved in dealing with the AmazingE 14-30 plug make the Grizzle-E the better deal unless you have a good reason to have a 14-30 plug or want a portable solution. If your LEAF is the 6 kW type then the Grizzl-E is the easy choice.
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By the way, in case 'EVSE' is causing some confusion:
The wall socket provides AC electricity. A 'charger' is inside the car and it converts AC to DC and sets the voltage the battery wants. The EVSE is a cable with safety electronics that connects the wall socket to the car. Its job is to negotiate the power flow, and to stop power flow if a safety condition pops up.
Some older LEAFs had a 3.3 kW charger (also called OBC for 'on board charger'.) Newer LEAFs have 6.6 kW
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The relation between Amps and watts
Amps * Volts = Watts
1 kW = 1000 watts
So e.g., if you have a 240 V socket and the LEAF can take 6.6 kW (6600 watts), then the LEAF can take 6600/240 = 27 Amps. A 3.3 kW LEAF can take 3300/240 = 14 Amps