async getCustomerForMemberCheckoutSession(member) {
        await member.related('stripeCustomers').fetch();
        const customers = member.related('stripeCustomers');
        for (const data of customers.models) {
            try {
                const customer = await this.getCustomer(data.get('customer_id'));
                if (!customer.deleted) {
                    return /** @type {ICustomer} */(customer);
                }
            } catch (err) {
                debug(`Ignoring Error getting customer for member ${err.message}`);
            }
        }

        debug(`Creating customer for member ${member.get('email')}`);
        const customer = await this.createCustomer({
            email: member.get('email')
        });

        return customer;
    }
Finds or creates a Stripe Customer for a Member.

@deprecated
@param {any} member

@returns {Promise<ICustomer>}