Disable prompt for RD gateway server credentials to login to client

i have installed server essentials 2012 r2 vet hospital (in testing phase right now) , trying remote access setup can login various client computers notes, @ records, lab results etc.  installation has gone pretty smoothly , got remote web access installed , working through anywhere access.  i've learned fair amount networking in process ran new when tried access client computer.

a new set of login credentials being asked under remote desktop gateway, , totally new me.  i tried first use various username , password credentials set server essentials, , when did not work moved on try find out rd gateway , how set or bypass it.  i found accessories app , explored of options there try bypass second login altogether, don't know how works.  do need go each client computer, app , disable credential login?  

what need simple - don't need second layer of security protect individual client computers information not privileged - new requirement hassle , want bypass requirement.  any on how appreciated. main reason want remote access in first place login client computers , access notes , data, stymied until figure out how around rd gateway security.

if not possible, need know , how set credentials each client because not apparent of googling either.

thanks in advance advice.

additional info if needed: clients running windows 10 pro, , joined them essentials network without joining domain, in workgroup mode.

Windows Server  >  Windows Server 2012 Essentials