I resolved this by following the guide here. I set the template.hbs to the below, see the addition of the phoneIcon
div:
{{#*inline 'phone'}}
{{#if card.phone}}
<div class="HitchhikerLocationStandard-phone">
<div class="HitchhikerLocationStandard-phoneIcon">
<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24"><path d="M4.827 10.387a20.198 20.198 0 008.786 8.786l2.934-2.933c.36-.36.893-.48 1.36-.32a15.21 15.21 0 004.76.76c.733 0 1.333.6 1.333 1.333v4.654C24 23.4 23.4 24 22.667 24 10.147 24 0 13.853 0 1.333 0 .6.6 0 1.333 0H6c.733 0 1.333.6 1.333 1.333 0 1.667.267 3.267.76 4.76.147.467.04.987-.333 1.36l-2.933 2.934z"></path></svg>
</div>
<a class="HitchhikerLocationStandard-desktopMobile"
href="tel:{{card.phone}}"
data-eventtype="TAP_TO_CALL"
data-eventoptions='{{json card.phoneEventOptions}}'
target="_top">
{{card.phone}}
</a>
</div>
{{/if}}
{{/inline}}
I then added the following to the answers.scss file:
.HitchhikerLocationStandard-phoneIcon {
height: 1em;
width: 1em;
margin-top: .1rem;
fill: black;
margin-right: .25rem;
}
The end result was as follows.