For the best results please follow these steps when exporting from Premiere:
File > Export > Media…
For resolutions up to full HD 1920 x 1080...
Set Format to ‘H.264’
Set Preset to ‘Match Source - Adaptive High Bitrate’
For 4K resolution...
Set Format to ‘HEVC (H.265)’
Set Preset to '4K UHD'
Select the Output Name to change the name of the output file and location.
Select ‘Queue’ (to queue in Adobe Media Encoder) or ‘Export’ (to export immediately from Premiere).