Convert to Algorithm

src/lib/ITensorMPS/src/mpo.jl

@@ -597,7 +597,7 @@ Equivalent to `replaceprime(contract(A, x; kwargs...), 2 => 1)`.
 See also [`contract`](@ref) for details about the arguments available.
 """
 function apply(A::MPO, ψ::MPS; alg=Algorithm"densitymatrix"(), kwargs...)
-  return apply(alg, A, ψ; kwargs...)
+  return apply(Algorithm(alg), A, ψ; kwargs...)
 end
 
 function apply(alg::Algorithm, A::MPO, ψ::MPS; kwargs...)