Good morning. Your employer cannot force you to apply for this position and whilst they can offer you the opportunity to apply, the final decision would rest with you. Unless there was a specific contractual clause which forced you to apply for such opportunities as they become available, which I doubt as I have not seen such clauses before, then it would be up to you as to when and if you apply for it.
If at present the opportunity is only provided on a fixed term basis, there is nothing stopping you from trying to negotiate with the employer to amend its terms and make it permanent. You could state that you are willing to apply for it but not in its current state and you would do so only if it was made permanent. It is basically down to you and the employer to agree on the position’s terms and if no suitable agreement can be reached then you do not have to apply for it, regardless of how keen the employer is for you to do so.
As to raising this issue with HR, that is not a formal requirement and it would depend on the structure of your employer, for example if HR have anything to do with the creation of the job or the process as a whole. Ideally you want to be speaking with whoever is in charge of recruitment and for creating the job, so whilst they could be HR, it could also be an individual, but as mentioned it does depend on the structure of the company and who is actually responsible for this.
Hope this clarifies your position? If you could please let me know that would be great, thank you
Please let me know if this has answered your original question or if you need me to clarify anything else for you in relation to this? Thanks