MERCADO_PAGO_SAMPLE_PUBLIC_KEY is not recognized as the name of

[cwrsiqueira]

MERCADO_PAGO_SAMPLE_PUBLIC_KEY=XXXXXX : The term 'MERCADO_PAGO_SAMPLE_PUBLIC_KEY=XXXXXX is not recognized as the name of a cmdlet, function, script
file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1

• MERCADO_PAGO_SAMPLE_PUBLIC_KEY=XXXXXX...

• 
  + CategoryInfo          : ObjectNotFound: (MERCADO_PAGO_SA...cd-3f0e0f27d1a1:String) [], CommandNotFoundException
  + FullyQualifiedErrorId : CommandNotFoundException

Como resolver esse erro? how do I solve this issue?

[SidSan97]

Conseguiu alguma solução?