Link that changes the src of the iframe?

Question

How to change the src of the iframe at the click of a button?

For example, I have this set of links:

<li class="hover">
    <a class="dropdown-toggle" href="#">
        <span class="menu-text"> Jucesp </span>
        <b class="arrow fa fa-angle-down"></b>
    </a>

	<b class="arrow"></b>

    <ul class="submenu">
        <li class="hover">
        <a href="https://www.jucesp.sp.gov.br/VRE/Consulta/ConsultaProcessos.aspx">
            <i class="menu-icon fa fa-caret-right"></i>
            Processo Integrado de Viabilidade e Registro
        </a>
    
            <b class="arrow"></b>
        </li>
    
        <li class="hover">
            <a href="https://www.sil.sp.gov.br/consultar_solicitacao.aspx">
                <i class="menu-icon fa fa-caret-right"></i>
                Processo de Licenciamento
            </a>
    
            <b class="arrow"></b>
        </li>
    
        <li class="hover">
            <a href="https://www.jucesponline.sp.gov.br/Pesquisa.aspx">
                <i class="menu-icon fa fa-caret-right"></i>
                Ficha Cadastral Completa
            </a>
    
            <b class="arrow"></b>
        </li>
    </ul>
</li>

And below a frame:

<iframe width="300" height="300">
    <p>Navegador não suporta <i>frames</i>.</p>
</iframe>

How to make so that when the user clicks on one of the links, it programmatically changes the src of iframe?

Preferably the easy way, since I’ll have to repeat the code 20 times.

EXAMPLE

The person clicked on the Integrated Feasibility Process..., instead of sending it to another URL, I want the iframe src to change to THAT CASE https://www.jucesp.sp.gov.br/VRE/Consulta/ConsultaProcessos.aspx