  The identification of complex prebiotic molecules using millimeter and
submillimeter telescopes allows us to understand how the basic building blocks
of life are formed in the universe. In the interstellar medium (ISM), ethylene
glycol ((CH$_{2}$OH)$_{2}$) is the simplest sugar alcohol molecule, and it is
the reduced alcohol of the simplest sugar-like molecule, glycolaldehyde
(CH$_{2}$OHCHO). We present the first detection of the rotational emission
lines of $aGg^{\prime}$ conformer of ethylene glycol ((CH$_{2}$OH)$_{2}$)
towards the hot molecular core G358.93$-$0.03 MM1 using the Atacama Large
Millimeter/Submillimeter Array (ALMA). The estimated column density of
$aGg^{\prime}$-(CH$_{2}$OH)$_{2}$ towards the G358.93$-$0.03 MM1 is
(4.5$\pm$0.1)$\times$10$^{16}$ cm$^{-2}$ with an excitation temperature of
155$\pm$35 K. The abundance of $aGg^{\prime}$-(CH$_{2}$OH)$_{2}$ with respect
to H$_{2}$ is (1.4$\pm$0.5)$\times$10$^{-8}$. Similarly, the abundances of
$aGg^{\prime}$-(CH$_{2}$OH)$_{2}$ with respect to CH$_{2}$OHCHO and CH$_{3}$OH
are 3.1$\pm$0.5 and (6.1$\pm$0.3)$\times$10$^{-3}$. We compare the estimated
abundance of $aGg^{\prime}$-(CH$_{2}$OH)$_{2}$ with the existing three-phase
warm-up chemical model abundance of (CH$_{2}$OH)$_{2}$, and we notice the
observed abundance and modelled abundance are nearly similar. We discuss the
possible formation pathways of $aGg^{\prime}$-(CH$_{2}$OH)$_{2}$ towards the
hot molecular cores, and we find that $aGg^{\prime}$-(CH$_{2}$OH)$_{2}$ is
probably created via the recombination of two CH$_{2}$OH radicals on the grain
surface of G358.93$-$0.03 MM1.
