Hi,
In such cases, the first thing to do is to activate the "display view files" setting in the Hikashop configuration and look at that area again.
You'll see that it is the view file checkout / show_block_address.php which is displayed the area where that button is.
Then, you can go in the Display>Views menu, search for that view file, and then search its code for that piece of HTML.
You'll see that it is this code displaying that HTML:
Code:
<button onclick="return window.checkout.submitAddress(<?php echo $this->step; ?>,<?php echo $this->module_position; ?>);" class="<?php echo $this->config->get('css_button','hikabtn'); ?> hikashop_checkout_address_ok_button"><i class="fa fa-save"></i> <?php echo JText::_('HIKA_OK'); ;?></button>
So there, you can change HIKA_OK by My text for that button.
Or even better, you could change it to MY_CUSTOM_TRANSLATION_KEY and then you can add a line:
MY_CUSTOM_TRANSLATION_KEY="My text for that button"
in your translation override, under the Languages tab of the HikaShop configuration in order to still use a translation key (useful if your website is in several languages or could be in the future).
