What is the ruling taught here for a male traveler praying a Fard prayer alone?

Adhan and Iqamah: Legal Status and Where They Are Prescribed

• They are not prescribed in travel.
• They remain within the Sunnah Mu'akkadah rule for Fard prayer, even when alone.
• They become Fard 'Ayn.
• Only Iqamah is forbidden.