For a PM, leveling up in a product org is a function of controllable inputs (e.g. performance, scope, execution, timeline delivery, consistency) and external factors that are beyond your direct control (e.g. organization funding and resource allocation, scope of role, growth of team, overall prioritization, leadership advocacy, etc.).

In your situation, it seems that you’re responsible for a key vertical, but it is not the highest priority within the organization. In this case, maximizing on the controllable inputs is a given, but to level up your career you will also need to influence the external factors. Here is my advice for you -

1. Scope expansion:

To level up you need to proactively expand the scope of your role, either within the current vertical or beyond. In most product orgs, PMs are expected to consistently perform at the next level (with increased scope) for a certain period of time (3-6 months) before being considered for a promotion to GPM.

One of the most natural ways to justify the request for scope expansion is demonstrable product growth. But if it is hard to demonstrate product growth/impact (since it isn't a revenue generating vertical) then you should consider taking on more responsibilities outside of your current vertical, wherever a fit seems natural. In your case, I would consider adding on PM responsibilities for the other verticals that are supported by the retail onboarding vertical.

2. Managing PMs:

As a GPM, one of the core responsibilities is to directly manage and lead a team of PMs. The transition from being an individual contributor to a group PM doesn’t come naturally to all (at least not to me).

To gain support from your manager and leadership, you’ll need to demonstrate the ability to delegate and lead fellow PMs in their roles. While you’re not expected to have prior management experience for a promotion, it certainly helps to show how you’ve built scalable frameworks, mechanisms and processes across teams for defining feature requirements, stakeholder management, driving prioritization, trade offs and data-driven decisions.

3. Leadership advocacy:

You will eventually need the right level of support and advocacy from your direct leadership to successfully transition to a “head of product” role. Typically, the leadership expects hard evidence on how you can consistently balance between big picture and details, effectively communicate (written and verbal) with your leadership, customers and key stakeholders, and most importantly, unblock your teams by defining a clear and scalable process for prioritization, trade-offs and data-driven decision making. To gain trust from your leadership, you should work proactively on collecting, documenting and sharing this evidence with them, and collecting their feedback for course correction, as and when needed.

In summary, you should continue to maximize on the controllable inputs (performance, consistency, execution), but to level up your career you will also need to influence the external factors, such as, scope expansion, leadership support, building scalable processes and stakeholder management.

My final advice is to vocalize your career goals to your manager and closely work with them on creating an action plan and timeline for achieving your career goals. This will be an iterative process so you should create intermediate milestones and regular checkpoints with your manager, so that you can learn, get constructive feedback, and course correct, if and when needed.