Add icon before Make Offer button Text

Can you tell me where makeOfferBtnhtml is controlled?

I want to add a FontAwesome icon before the Make Offer text by modifying the button element in html to include before::

Example Code

<button type="button" id="offers-for-woocommerce-make-offer-button-id-5981" class="offers-for-woocommerce-make-offer-button-single-product  offers-for-woocommerce-make-offer-button-single-product-lightbox button alt" style="color:#FFFFFF!important; background:#6CC200!important; border-color:#6CC200!important;">
  ::before
  "Make Offer"</button>

and this CSS

.offers-for-woocommerce-add-to-cart-wrap.ofwc-button-right-of-add-to-cart .offers-for-woocommerce-make-offer-button-single-product:before {
    display: inline-block; content: "\f07a"; font-family: "FontAwesome";margin-right:0.7143em; }

Is this the correct way to do this? If so can you tell me where to modify the “makeOfferBtnhtml” that is being called in the public.js file on line 54-56 shown below:

// before add to cart (after single_variation)
                if(makeOfferBtnPosition == 'before_add') {
                    $('#offers-for-woocommerce-add-to-cart-wrap div:first').before("<div class='offers-for-woocommerce-add-to-cart-wrap ofwc-no-float'>" + <strong>makeOfferBtnhtml</strong> + "");

https://ww.wp.xz.cn/plugins/offers-for-woocommerce/