To install the current stable version of QuantumElectrodynamics.jl, you may use the standard julia package manager within the julia REPL:
julia> using Pkg
julia> Pkg.add("QuantumElectrodynamics")or you use the Pkg prompt by hitting ] within the Julia REPL and then type
(@v1.10) pkg> add QuantumElectrodynamicsTo install the locally downloaded package on Windows, change to the parent directory and type within the Pkg prompt
(@v1.10) pkg> add ./QuantumElectrodynamics.jl