Im wondering what this string or bytes would be sent in a post request

Question

The value I\'m looking to understand is FlJ+FEF8CFiD/LMG.LUWUHskIj0OI9snp08hBWaMSSO1oP/DPgpmnYIc0DBLtSWMEsKgZvSTsWlw38w1+6NDEr2Za+7683gwbVXSQ/Gd+MsrnCXzwJXkdZN+WBaIuQm