help me on how to create this hash

hi
i am try to find out how should create this type of hash

data is : {"logonId":"admin@admin.com","logonPassword":"123456"}

and the hash will appear to this data is :

xIyI5v15kQq1nrKxv7mqlJQV0bwQ8IFfucrb7AC2iAgrWAEAAFC3f6-DGHZzUTQa9frcq3RLPmXg5gzk2oluelCMhu1iGn3mag==


i dont know how should create it

like base64(email:pass)
or base64(md5(email:pass))

or put the whole {"logonId":"admin@admin.com","logonPassword":"123456"}
instead of email:pass


hope you guys could help me