Hi Loris - sorry to hear you are struggling.
The three factors that need to be considered are:
1. Time when you offer her the bottle - is there enough time from when she fed last to now for her to be hungry.
2. The formula - is it mixed correctly and is the temperature as close to 37 degrees as you can get it, so that it mimics your body temperature (that is the milk temperature she usually drinks at.)
3. Look at the bottle and teat you are offering - all babies have thier own preference and can pretty much adjust to what ever they are presented with. However the wide neck and wide teat is pretty similiar in shape to a breast, so babies seem to like this.
Okay, so once you have worked out the above and gone yes, yes, done, then the next issue is - you need to not be there.
If you are there or you are offering her the bottle, she can smell your milk all over you, and why should she take the bottle when you have what she wants and if she cries and gets fussy you will be able to offer it to her.
I suggest you feed her, do what ever you need to do and then leave the house for a good six - eight hours. Get out of the house, not just hiding in a bedroom.
If her feeding is at 1pm, then the carer/your partner will offer her the bottle then, she might resist and push it away, but odds are she is not that hungry.
And he can try again in another 30 minutes.
At some point - she will realise she is hungry, and the bottle will be available and she will drink it.
She might resist further if you are in the house - even if you are hiding away in another room as she can smell you, and will rather push the bottle away and cry for you.
It might take some perseverance from the feeder as she might get fussy, but by holding her securely, pushing the bottle in her mouth until she gets the taste, she will probably then start to suck and all will be well.
Of course this might not work, but it is probably a good recipe if you are struggling to feed her yourself to get the ball rolling.
Once you introduce the bottle, your baby might well reject the breast - some babies don't and can happily switch between the two.
Good luck.